Effects Of Growth Differentiation Factor Research Articles

GDF11: An emerging therapeutic target for liver diseases and fibrosis.

Growth differentiation factor 11 (GDF11), also known as bone morphogenetic protein 11 (BMP11), has been identified as a key player in various biological processes, including embryonic development, aging, metabolic disorders and cancers. GDF11 has also emerged as a critical component in liver development, injury and fibrosis. However, the effects of GDF11 on liver physiology and pathology have been a subject of debate among researchers due to conflicting reported outcomes. While some studies suggest that GDF11 has anti-aging properties, others have documented its senescence-inducing effects. Similarly, while GDF11 has been implicated in exacerbating liver injury, it has also been shown to have the potential to reduce liver fibrosis. In this narrative review, we present a comprehensive report of recent evidence elucidating the diverse roles of GDF11 in liver development, hepatic injury, regeneration and associated diseases such as non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), liver fibrosis and hepatocellular carcinoma. We also explore the therapeutic potential of GDF11 in managing various liver pathologies.

The regulatory effect of growth differentiation factor 11 on different cells.

Growth differentiation factor 11 (GDF11) is one of the important factors in the pathophysiological process of animals. It is widely expressed in many tissues and organs of animals, showing its wide biological activity and potential application value. Previous research has demonstrated that GDF11 has a therapeutic effect on various diseases, such as anti-myocardial aging and anti-tumor. This has not only sparked intense interest and enthusiasm among academics but also spurred some for-profit businesses to attempt to develop GDF11 as a medication for regenerative medicine or anti-aging application. Currently, Sotatercept, a GDF11 antibody drug, is in the marketing application stage, and HS-235 and rGDF11 are in the preclinical research stage. Therefore, we believe that figuring out which cells GDF11 acts on and its current problems should be an important issue in the scientific and commercial communities. Only through extensive, comprehensive research and discussion can we better understand the role and potential of GDF11, while avoiding unnecessary risks and misinformation. In this review, we aimed to summarize the role of GDF11 in different cells and its current controversies and challenges, providing an important reference for us to deeply understand the function of GDF11 and formulate more effective treatment strategies in the future.

Oocyte-derived growth differentiation factor 9 suppresses the expression of CYP17A1 and androgen production in human theca cells

ObjectiveTo investigate the direct effect of growth differentiation factor 9 (GDF9) on androgen production in human theca cells. DesignExperimental study SettingTertiary hospital-based research laboratory Patient(s)Women underwent IVF/intracytoplasmic sperm injection (ICSI) at our clinic were included in this study. Intervention(s)Primary cultured human theca cells from women undergoing IVF/ICSI treatment were treated with GDF9, Activin receptor-like kinase 5 (ALK5) inhibitor, and SMAD4 agonist. Main Outcome Measure(s)The expression of androgen synthesis-related gene StAR, CYP17A1, and LHCGR, levels of androstenedione and testosterone, phosphorylation of SMAD2/3 and the interaction between bone morphogenetic protein receptor II (BMPRII) and ALK5 were evaluated by RT-qPCR, Western blot, enzyme-linked immunosorbent assays, and co-immunoprecipitation assays respectively. ResultsGDF9 decreased StAR, CYP17A1, and LHCGR expression levels in human theca cells, which was prevented by the treatment with the ALK5 inhibitor, and suppressed production of androgen in human theca cells. GDF9 increased SMAD2/3 phosphorylation, and the ALK5 inhibitor also suppressed this effect. BMPRII and ALK5 bound to each other following GDF9 stimulation. The SMAD4 agonist kartogenin also decreased mRNA levels of StAR and CYP17A1, and protein levels of StAR in human theca cells. ConclusionGDF9 can activate the BMPRII-ALK5-SMAD2/3 signaling pathway, suppress CYP17A1 expression and androgen production in human theca cells.

GDF-11 downregulates placental human chorionic gonadotropin expression by activating SMAD2/3 signaling

BackgroundThe production of human chorionic gonadotropin (hCG) by the placental trophoblast cells is essential for maintaining a normal pregnancy. Aberrant hCG levels are associated with reproductive disorders. The protein of hCG is a dimer consisting of an α subunit and a β subunit. The β subunit is encoded by the CGB gene and is unique to hCG. Growth differentiation factor-11 (GDF-11), a member of the transforming growth factor-β (TGF-β) superfamily, is expressed in the human placenta and can stimulate trophoblast cell invasion. However, whether the expression of CGB and the production of hCG are regulated by GDF-11 remains undetermined.MethodsTwo human choriocarcinoma cell lines, BeWo and JEG-3, and primary cultures of human cytotrophoblast (CTB) cells were used as experimental models. The effects of GDF-11 on CGB expression and hCG production, as well as the underlying mechanisms, were explored by a series of in vitro experiments.ResultsOur results show that treatment of GDF-11 downregulates the expression of CGB and the production of hCG in both BeWo and JEG-3 cells as well as in primary CTB cells. Using a pharmacological inhibitor and siRNA-mediated approach, we reveal that both ALK4 and ALK5 are required for the GDF-11-induced downregulation of CGB expression. In addition, treatment of GDF-11 activates SMAD2/3 but not SMAD1/5/8 signaling pathways. Moreover, both SMAD2 and SMAD3 are involved in the GDF-11-downregulated CGB expression. ELISA results show that the GDF-11-suppressed hCG production requires the ALK4/5-mediated activation of SMAD2/3 signaling pathways.ConclusionsThis study not only discovers the biological function of GDF-11 in the human placenta but also provides important insights into the regulation of the expression of hCG.EYYrMgGK1oNKot-fDMBUfiVideo

Effect of growth differentiation factor 11 expression after peripheral nerve injury in Sprague-Dawley rats

ABSTRACT Objectives We attempt to investigate the expression pattern of GDF11 in the sciatic nerves after injury. Methods Thirty-six healthy male Sprague Dawley (SD) rats were divided into three groups at random and were labelled as: day 1, day 4, and day 7 post-surgery. The sciatic nerve crush model was established on the left-hind limb, while the right limb was untreated, and served as the control. Nerve samples were collected at post-injury day 1, day 4 and day 7. Nerve samples collected from the proximal and distal stump of the injury site underwent immunofluorescence staining with GDF11, NF200 and CD31. GDF11 mRNA expression was analyzed by qRT-PCR. CCK-8 assay, after si-GDF11 transfection in Schwann cells (RSC96) was applied to verify its effect in cell proliferation rate. Results GDF11 was abundantly expressed in axons stained with NF200 and Schwann cells stained with S100. However, no GDF11 expression was observed in vascular endothelial tissues stained with CD31. From day 4 onwards, the level of GDF11 showed an increasing trend, up to a twofold level at day 7 after injury. Proliferation rate of RSC96 cells showed a significant decrease after the down-regulation of GDF11 by siRNAs compared to the control group. Conclusions GDF11 may play a role in the proliferation of Schwann cell during nerve regeneration process.

Screening study of anti-emetics to improve GDF15-induced malaise and anorexia: Implications for emesis control

Considerable preclinical and clinical attention has focused on the food intake and body weight suppressive effects of growth differentiation factor 15 (GDF15) and its elevated blood levels as a consequence of disease states and disease treatment therapeutics. We have previously reported that exogenous administration of GDF15 induces anorexia through nausea and emesis in multiple species. Importantly, GDF15 signaling as a meditator of chemotherapy-induced anorexia and emesis has recently been demonstrated in both murine and nonhuman primate models. The mechanism, however, by which GDF15 induces malaise and the utility of existing therapeutic targets to counteract its effects remain largely unknown. Using a dose of GDF15 that mimics stimulated levels following chemotherapy administration and reliably induces malaise, we sought to screen anti-emetics that represent distinct pharmacotherapeutic classes hypothesized to reduce GDF15-induced effects in rats. Strikingly, our results showed that none of the tested compounds were effective at preventing GDF15-induced malaise. These results illustrate the complexity of GDF15 signaling mechanism and may have important implications for medical conditions characterized by elevated GDF15 levels and incomplete symptom control, such as chemotherapy-induced nausea and vomiting.

Renoprotective and anti-inflammatory effects of growth differentiation factor 15 (GDF15) in mice with diet-induced obesity

Growth differentiation factor 15 (GDF15) is a stress-responsive cytokine studied recently for its role in multiple biological processes and diseases. This transforming growth factor beta (TGF-b) family member has been investigated as a therapeutic agent and biomarker for obesity and associated cardiovascular diseases. Studies have shown the anti-inflammation, anti-obesity, and anti-diabetic effects of GDF15, but few have focused on the role of GDF15 in the kidneys. In this study, we hypothesized that GDF15 ameliorates obesity-induced inflammation and fibrosis in the kidney. We treated wild-type (WT) and GDF15 transgenic (NAG) mice with high-fat diets (HFD) (42% calories from fat) or normal chow. Analysis of four groups of mice (WT, WT+HFD, NAG, and NAG+HFD) illustrated significantly reduced levels of kidney fibrosis (a-SMA, TGF-b) and inflammation (NFkB, TNF-a) in the NAG with HFD mice. The kidney injury markers NGAL and TIM-1 were significantly reduced in the NAG+HFD mice. We also found decreased urinary norepinephrine excretion and serum creatinine, and increased glomerular filtration rate, urine volume, and sodium excretion in GDF15 transgenic mice with HFD. Further, in vitro study showed that GDF15 treatment reduced norepinephrine-induced kidney fibrosis and pro-inflammatory cytokine production in cultured kidney HK-2 and LLC cells. These results suggest GDF15 is a possible therapeutic target for kidney injury via its anti-inflammatory and anti-fibrosis protective effects. Funded by NIH R01-DK-114663 & R01-DK-129311 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Renoprotection by GDF15 and Klotho: birds of a feather flock together

Growth differentiation factor 15 is a potential renoprotective factor whose expression is induced primarily at the proximal tubular site after kidney injury. Valiño-Rivas etal. confirmed the protective effect of growth differentiation factor 15 against different types of kidney injury and further identified that growth differentiation factor 15 also induces kidney expression of another renoprotective factor, Klotho. Surprisingly, Klotho expression is apparently enhanced in the proximal tubule, suggesting the cooperative action of the 2 renoprotective factors at this injury-prone site.

Protective effect of growth differentiation factor 15 in sepsis by regulating macrophage polarization and its mechanism

ABSTRACT This study aims to investigate the protective effect of growth differentiation factor 15 (GDF15) in sepsis by regulating macrophage polarization and its mechanism. The mouse macrophages were cultured and treated with lipopolysaccharide (LPS), and some cells were intervened with GDF15 and LY294002. The proinflammatory activated (M1) macrophages and the anti-inflammatory activated (M2) macrophages were measured and observed, and the messenger RNA expression levels of their biomarkers, phosphatidylinositol 3-kinase (PI3K), and protein kinase B (Akt) were detected. The survival rate, cardiac function, and histopathological sections were observed. In the LPS group, after GDF15 intervention, the percentage of M1 macrophages decreased and M2 macrophages increased, the infiltration of monocytes/macrophages into the heart was inhibited, systemic and cardiac inflammation was reduced, and the survival time of the mice was prolonged. GDF15 regulated macrophage polarization and played an anti-inflammatory role by activating the phosphorylation of the PI3K/Akt signaling pathway. In patients with sepsis, the serum GDF15 level increased and was closely related to the severity of the sepsis and the 28-day mortality rate and could be used as a prognostic marker of sepsis. GDF15 regulates macrophage polarization through activating the PI3K/Akt signaling pathway and has a protective effect on survival and the cardiac function of patients with sepsis and sepsis mouse models. The increase in serum GDF15 level is closely related to severity and mortality in patients with sepsis and is therefore a prognostic marker of sepsis.

Growth differentiation factor 15 (GDF15) and semaglutide inhibit food intake and body weight through largely distinct, additive mechanisms.

To evaluate whether the potent hypophagic and weight-suppressive effects of growth differentiation factor-15 (GDF15) and semaglutide combined would be a more efficacious antiobesity treatment than either treatment alone by examining whether the neural and behavioural mechanisms contributing to their anorectic effects were common or disparate. Three mechanisms were investigated to determine how GDF15 and semaglutide induce anorexia: the potentiation of the intake suppression by gastrointestinal satiation signals; the reduction in motivation to feed; and the induction of visceral malaise. We then compared the effects of short-term, combined GDF15 and semaglutide treatment on weight loss to the individual treatments. Rat pharmaco-behavioural experiments assessed whether GDF15 or semaglutide added to the satiating effects of orally gavaged food and exogenous cholecystokinin (CCK). A progressive ratio operant paradigm was used to examine whether GDF15 or semaglutide reduced feeding motivation. Pica behaviour (ie, kaolin intake) and conditioned affective food aversion testing were used to evaluate visceral malaise. Additionally, fibre photometry studies were conducted in agouti-related protein (AgRP)-Cre mice to examine whether GDF15 or semaglutide, alone or in combination with CCK, modulate calcium signalling in hypothalamic AgRP neurons. Semaglutide reduced food intake by amplifying the feeding-inhibitory effect of CCK or ingested food, inhibited the activity of AgRP neurons when combined with CCK, reduced feeding motivation and induced malaise. GDF15 induced visceral malaise but, strikingly, did not affect feeding motivation, the satiating effect of ingested food or CCK signal processing. Combined GDF15 and semaglutide treatment produced greater food intake and body weight suppression than did either treatment alone, without enhancing malaise. GDF15 and semaglutide reduce food intake and body weight through largely distinct processes that produce greater weight loss and feeding suppression when combined.

Cardioprotective Effect of Growth Differentiation Factor 15 Against Isoproterenol-Induced Cardiomyocyte Apoptosis via Regulation of the Mitochondrial Fusion

Abstract Objective: Pressure overload-induced myocardial apoptosis is a critical pathologically initiated process leading to heart failure (HF). Growth differentiation factor 15 (GDF15) dramatically increases during cardiac hypertrophy and dysfunction, but its functions and mechanisms are barely known. This study aims to elucidate the role and mechanism of GDF15 in HF. Methods: Between January 2017 and August 2018, 57 patients diagnosed with chronic HF (aged >18 years, with left ventricular ejection fraction (LVEF) ≤35%) and 57 non-HF patients (aged >18 years, LVEF >35%) were prospectively enrolled in this study based on the balance of the baseline characteristics. Other acute or chronic diseases and pregnant/lactating women were excluded. The serum concentrations of GDF15 were detected. Isoproterenol (ISO)-induced HF mouse model was established by pumping with ISO (30 mg/(kg·day)) for 4 weeks, and the GDF15 expression in serum and heart tissue was evaluated in vivo. Primary cardiomyocytes were cultured and treated with ISO to induce cardiomyocytes damage. The apoptosis of cardiomyocytes and the effect of GDF15 on ISO-induced cardiomyocytes injury was evaluated in vitro. Results: After adjusting the baseline characteristic, serum levels of GDF15 were significantly higher in HF subjects than in non-HF patients. Similarly, in the ISO-induced HF mouse model, the significant increase in GDF15 was associated with the process of HF in vivo. Moreover, the elevation of GDF15 occurred prior to heart remodeling in the ISO-induced HF mouse model. Furthermore, using primary cardiomyocytes, we demonstrated that the GDF15 was remarkably enhanced in serum from pathological HF patients and cardiac tissue from the ISO-induced mouse model. Reducing GDF15 exaggerated the ISO-induced cell apoptosis by blocking mitochondrial fusion and increasing oxidative stress. In contrast, the silence of GDF15 aggravated the ISO-induced cardiomyocytes damage. Conclusions: GDF15 acts as a protective factor against cardiomyocyte apoptosis by improving mitochondria fusion during HF. These findings indicate that GDF15 may be a potential therapeutic target for HF.

Effect of growth differentiation factor 11 on the steatosis of condylar chondrocytes in temporomandibular joint osteoarthritic mice.

To observe the effect of growth differentiation factor 11 (GDF11) on the steatosis of condylar chondrocytes in temporomandibular joint (TMJ) osteoarthritic mice. Six-week-old female C57 mice were stimulated with unilateral anterior crossbite (UAC) and locally injected with GDF11. TMJ sections were stained with safranin O, and GDF11 and Adiponectin in the TMJ cartilage were detected by immunohistochemical staining. GDF11, Adiponectin, type Ⅱ collagen (Col-Ⅱ), Aggrecan, type Ⅰ collagen (Col-Ⅰ), fatty acid-binding protein 4 (FABP4), and Perilipin 1 mRNA were detected by real-time polymerase chain reaction (real-time PCR). The thickness and safranin O-positive area of TMJ cartilage in the UAC groups, as well as the mRNA expression of Col-Ⅱ and aggrecan, significantly decreased. The ratio of Adiponectin-positive cells significantly increased. The mRNA expression levels of Col-Ⅰ, Adiponectin, FABP4, and Perilipin 1 significantly increased. The TMJ cartilage of the GDF11 injection groups significantly thickened, and the safranin O-positive area significantly increased. The mRNA expression of Col-Ⅱ and Aggrecan significantly increased. The ratio of Adiponectin-positive cells significantly decreased. The mRNA expression levels of Col-I, Adiponectin, FABP4, and Perilipin 1 significantly decreased. Extensive steatosis of chondrocytes and decreased expression of GDF11 in the degenerated cartilage of TMJ osteoarthritis are induced by UAC stimulation. Supplementation of exogenous GDF11 can effectively inhibit the steatosis of chondrocytes.

GDF11 alleviates neointimal hyperplasia in a rat model of artery injury by regulating endothelial NLRP3 inflammasome activation and rapid re-endothelialization

BackgroundNeointimal hyperplasia induced by interventional surgery can lead to progressive obliteration of the vascular lumen, which has become a major factor affecting prognosis. The rate of re-endothelialization is known to be inversely related to neointima formation. Growth differentiation factor 11 (GDF11) is a secreted protein with anti-inflammatory, antioxidant, and antiaging properties. Recent reports have indicated that GDF11 can improve vascular remodeling by maintaining the differentiated phenotypes of vascular smooth muscle cells. However, it is not known whether and how GDF11 promotes re-endothelialization in vascular injury. The present study was performed to clarify the influence of GDF11 on re-endothelialization after vascular injury.MethodsAn adult Sprague–Dawley rat model of common carotid artery balloon dilatation injury was surgically established. A recombinant adenovirus carrying GDF11 was delivered into the common carotid artery to overexpress GDF11. Vascular re-endothelialization and neointima formation were assessed in harvested carotid arteries through histomolecular analysis. CCK-8 analysis, LDH release and Western blotting were performed to investigate the effects of GDF11 on endothelial NLRP3 inflammasome activation and relevant signaling pathways in vitro.ResultsGDF11 significantly enhanced re-endothelialization and reduced neointima formation in rats with balloon-dilatation injury by suppressing the activation of the NLRP3 inflammasome. Administration of an endoplasmic reticulum stress (ER stress) inhibitor, 4PBA, attenuated endothelial NLRP3 inflammasome activation induced by lysophosphatidylcholine. In addition, upregulation of LOX-1 expression involved elevated ER stress and could result in endothelial NLRP3 inflammasome activation. Moreover, GDF11 significantly inhibited NLRP3 inflammasome-mediated endothelial cell pyroptosis by negatively regulating LOX-1-dependent ER stress.ConclusionsWe conclude that GDF11 improves re-endothelialization and can attenuate vascular remodeling by reducing endothelial NLRP3 inflammasome activation. These findings shed light on new treatment strategies to promote re-endothelialization based on GDF11 as a future target.

Growth differentiation factor 11 accelerates liver senescence through the inhibition of autophagy.

The “rejuvenating” effect of growth differentiation factor 11 (GDF11) is called into question recently, and its role, as well as plausible signaling mechanisms in liver senescence, is unclear. To overexpress or knockdown GDF11, aged male mice are injected with a single dose of adeno‐associated viruses‐GDF11 or adenovirus‐small hairpin RNA‐GDF11, respectively. GDF11 overexpression significantly accelerates liver senescence in aged mice, whereas GDF11 knockdown has opposite effects. Concomitantly, autophagic flux is impaired in livers from GDF11 overexpression mice. Conversely, GDF11 knockdown increases autophagic flux. Moreover, rapamycin successfully restores the impaired autophagic flux and alleviates liver senescence in GDF11 overexpression mice, while the GDF11 knockdown‐mediated benefits are abolished by the autophagy inhibitor bafilomycin A1. GDF11 leads to a drop in lysosomal biogenesis resulting in defective autophagic flux at autophagosome clearance step. Mechanistically, GDF11 significantly activates mammalian target of rapamycin complex 1 (mTORC1) and subsequently represses transcription factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy. Inhibition of mTORC1 or TFEB overexpression rescues the GDF11‐impaired autophagic flux and cellular senescence. Hepatocyte‐specific deletion of GDF11 does not alter serum GDF11 levels and liver senescence. Collectively, suppression of autophagic activity via mTORC1/TFEB signaling may be a critical molecular mechanism by which GDF11 exacerbates liver senescence. Rather than a “rejuvenating” agent, GDF11 may have a detrimental effect on liver senescence.

Associations of GDF-15 and GDF-15/adiponectin ratio with odds of type 2 diabetes in the Chinese population.

We elucidate the effect of Growth differentiation factor-15(GDF-15)/adiponectin ratio in improving the assessment value for odds of type 2 diabetes. Cross-sectional design. A total of 405 participants (135 patients with newly diagnosed type 2 diabetes, 135 age- and sex-matched participants with prediabetes, and 135 healthy controls) were collected from Guangzhou and Dongguan, China. The serum GDF-15 and adiponectin levels were measured by ELISA and latex-enhanced immunoturbidimetry. Logistic regression analysis and restricted cubic splines were used to evaluate the associations between diabetes and the indicators. The low level of adiponectin and high GDF-15/adiponectin ratio were significantly associated with increased odds of type 2 diabetes, but not for GDF-15. Three clusters were identified based on the K-means clustering analysis. Compared to the lowest quartiles of adiponectin, the OR and 95% CI of the highest adiponectin with type 2 diabetes was 0.24 (0.07-0.74, p trend = 0.004) after adjusting for sex, age, BMI, and DBP only in cluster 1. After adjusting for confounding factors, subjects with the highest GDF-15/adiponectin ratio quartiles had 3.9 times (OR = 3.85, 95% CI = 0.76-24.25) and 3.8 times (OR = 3.80, 95% CI = 1.02-14.68) higher odds of type 2 diabetes in cluster 2 and cluster 3, respectively. The association between the GDF-15/adiponectin ratio and type 2 diabetes was attenuated, but still remarkable (OR = 3.18, 95% CI = 1.11-10.18), in cluster 1. Higher GDF-15/adiponectin ratio is independently associated with increased odds of type 2 diabetes for all study populations, suggesting that the GDF-15/adiponectin ratio may be a better indicator of type 2 diabetes.

GDF11 alleviates secondary brain injury after intracerebral hemorrhage via attenuating mitochondrial dynamic abnormality and dysfunction

Intracerebral hemorrhage (ICH) is a serious public health problem with high rates of death and disability. The neuroprotective effect of Growth Differentiation Factor 11 (GDF11) in ICH has been initially proved by our previous study. Oxidative stress (OS) plays crucial roles in mediating subsequent damage of ICH. However, whether and how mitochondrial dynamic events and function participated in ICH pathophysiology, and how mitochondrial function and OS interreacted in the neuroprotective process of GDF11 in ICH remains unclarified. Based on the rat model of ICH and in vitro cell model, we demonstrated that GDF11 could alleviate ICH induced neurological deficits, brain edema, OS status, neuronal apoptosis and inflammatory reaction. In addition, mitochondrial functional and structural impairments were obviously restored by GDF11. Treatment with antioxidant protected against erythrocyte homogenate (EH) induced cell injury by restoring OS status and mitochondrial fusion fission imbalance, which was similar to the effect of GDF11 treatment. Further, inhibition of mitochondrial division with Mdivi-1 attenuated mitochondrial functional defects and neuronal damages. In conclusion, our results for the first time proposed that GDF11 protected the post-ICH secondary injury by suppressing the feedback loop between mitochondrial ROS production and mitochondrial dynamic alteration, resulting in attenuated mitochondrial function and amelioration of neural damage.

Effect of growth differentiation factor 9 (GDF-9) on in vitro development of collared peccary preantral follicles in ovarian tissues

The aims were to identify the effects of growth differentiation factor 9 (GDF-9) on the in vitro development of ovarian preantral follicles (PAFs) of collared peccaries. Ovarian fragments were in vitro cultured for 1 or 7 days without or with inclusion of GDF-9 in the medium (0, 50, 100, or 200 ng/mL). The non-cultured (control) and cultured fragments were evaluated for PAF viability, activation, and cell proliferation. Although there were no differences in the percentage of morphologically normal follicles, the percentage of growing follicles was greater compared to the control in all treatment groups, especially those cultured with 200 ng/mL GDF-9 for 7 days (P < 0.05). The inclusion of GDF-9 in the medium did not interfere with PAF viability (P> 0.05); however, treatment with 200 ng/mL GDF-9 resulted in greater (P < 0.05) cell proliferation in PAFs cultured for 1 or 7 days (∼2.5 nucleolar organizing regions – NORs) compared to the follicles of the control group (2.0 NORs). In addition, peccary ovarian cortexes were subjected to PCR analysis and there was detection of the mRNA GDF-9 receptor transcripts of the BMPR2 (type I receptor) and ALK-5 (type II receptor) types. In conclusion, GDF-9, especially at a 200 ng/mL inclusion in the culture medium, was actively involved in the in vitro development of collared peccary PAFs.

Effect of growth differentiation factor 15 (GDF-15) inhibition on energy balance in cancer cachexia and in lipopolysaccharide (LPS)-induced sepsis mouse models.

e24153 Background: Growth differentiation factor 15 (GDF-15) is a cytokine that induces anorexia, weight loss and has been reported to be associated with cachexia and poor survival in illnesses characterized by inflammation such as cancer cachexia and heart failure. In preclinical cancer cachexia models, GDF-15 inhibition has been demonstrated to reverse cachexia and improve survival. Circulating GDF-15 is also elevated in patients with sepsis and is associated with increased complications and poor survival. However, the role of infection- and sepsis-induced GDF-15 in mouse models is controversial based on published reports. Methods: In this study, we examined the effect of GDF-15 inhibition on tumor and lipopolysaccharide (LPS)-induced anorexia, weight loss, and survival using a GDF-15 neutralizing antibody (mAB2) and GDF-15 knockout mice. Results: mAB2 efficacy was confirmed by reversing AAV-GDF-15-induced weight loss in wildtype mice. A cachectic (anorexia and weight loss) mouse tumor model was established with subcutaneous implantation of mouse renal cell carcinoma (RENCA) cells. The chemotherapy sorafenib was administered to slow tumor progression. Plasma GDF-15 was increased to ~2 ng/mL, similar to levels in cancer patients. Treatment with mAB2 rapidly reversed both anorexia and weight loss in the tumor-bearing mice. LPS injection (intraperitoneal, 5 mg/kg) increased circulating GDF-15 in wildtype mice reaching concentrations like that reported in septic patients within 90 minutes and remaining elevated after 48 hours (~1 ng/mL). LPS decreased food intake, body weight, and increased mortality (~20%). Different from the tumor model, GDF-15 neutralization with mAB2 did not prevent or exacerbate any of the effects of LPS. There were no observed detrimental effects of mAB2 treatment in either model. Similarly, in GDF-15 knockout mice the LPS effect on energy balance and survival was comparable to that observed in wildtype controls. Plasma GDF-15 was undetectable in the GDF-15 knockout mice. Conclusions: Taken together, these data suggest that GDF-15 is a critical regulator of energy balance and survival in selective pathophysiological states associated with weight loss.

Growth differentiation factor 15 facilitates lung fibrosis by activating macrophages and fibroblasts

Lung fibrosis is a devastating disease characterized by fibroblast accumulation and extracellular matrix deposition in lungs. However, its molecular and cellular pathogenesis is not fully understood and the current therapeutic strategies are ineffective. Bleomycin-induced lung fibrosis is the most widely used experimental model for research aimed at in-depth analysis of lung fibrosis mechanisms. The present study aimed to analyse the effects of growth differentiation factor 15 (GDF15), which is associated with many diseases, in lung fibrosis. GDF15 mRNA expression was elevated in the lungs of bleomycin-treated mice, revealed by comprehensive gene analysis. Its protein levels were also increased in the lungs, bronchoalveolar lavage fluid, and plasma obtained from bleomycin-treated mice as compared to those in saline-treated mice. Bleomycin administration in mice resulted in a marked increase in senescence-associated β-galactosidase-positive and p16INK4a-positive lung structural cells including alveolar epithelial cells and macrophages. Immunohistochemical staining using anti-GDF15 antibody and increased mRNA expression of GDF15 in bleomycin-induced senescent A549 cells indicated that GDF15 is produced from alveolar epithelial cells undergoing bleomycin-induced cellular senescence. GDF15 was also implicated in the augmentation of interleukin-4/interleukin-13-induced mRNA expression of M2 markers including arginase 1 and chitinase-3-like protein and was also responsible for increased α-smooth muscle actin expression through the ALK5-Smad2/3 pathway in WI-38 lung fibroblasts. Therefore, GDF15 secreted from senescent alveolar epithelial cells might act as a profibrotic factor through activation of M2 macrophages and fibroblasts. This implies that GDF15 could be a potential therapeutic target and a predictor of lung fibrosis progression.

GDF15 Induces an Aversive Visceral Malaise State that Drives Anorexia and Weight Loss

The anorectic and weight-suppressive effects of growth differentiation factor-15 (GDF15) are attracting considerable attention for treating obesity. Current experiments in rats investigate whether GDF15 induces an aversive visceral malaise-based state that mediates its acute anorectic effect and, through aversion conditioning, exerts longer-term anorexia. Visceral malaise, conditioned affective food responses (taste reactivity), gastric emptying (GE), food intake, and body weight are evaluated after acute and chronic systemic dosing of GDF15 or long-acting Fc-GDF15. Pica, a marker of visceral malaise, is present at all anorectic GDF15 doses. Moreover, malaise induced by GDF15 does not decline over time, suggesting the lack of an improved tolerance after prolonged exposure. One association between GDF15 and novel food conditions a disgust/aversive response that persists beyond GDF15 acuteaction. Delayed GE is not a requirement for GDF15-induced anorexia. Clinical studies are required to evaluate whether GDF15's aversive-state-based anorexia will be contraindicated as an obesity treatment.