Progress in the relationship between GDF11 and depression.

Annually, the frequency of morbidity in depression has increased progressively in response to life stressors, and there is an increasing trend toward younger morbidity. The pathogenesis of depression is complicated and includes factors such as genetic inheritance and variations in physiological functions induced by various environmental factors. Currently, drug therapy has wide adaptability in clinical practice and plays an important role in the treatment of patients with mild depression. However, the therapeutic effects of most antidepressants are typically not significant and are associated with considerable adverse effects and addiction. Therefore, it is imperative to identify the deeper mechanisms of depression and search for alternative drug targets. Growth differentiation factor 11 (GDF11) is described as an anti-ageing molecule that belongs to a member of the transforming growth factor ß family. Additionally, the latest research findings suggested that GDF11 positively regulates neurogenesis and enhances neuronal activity, thereby attenuating depression-like behaviours. Although an increasing number of studies have focused on the multiple functions of GDF11 in skeletal dysplasia and carcinogenesis, its precise mechanism of action in depression remains unknown. Thus, in this review, we discuss the role of GDF11 and its mechanistic pathways in the pathogenesis of depression to develop novel therapies for depression.

GDF11 mitigates high glucose-induced cardiomyocytes apoptosis by inhibiting the ALKBH5-FOXO3-CDR1as/Hippo signaling pathway.

Diabetic cardiomyopathy remains a formidable health challenge with a high mortality rate and no targeted treatments. Growth differentiation factor 11 (GDF11) has shown promising effects on cardiovascular diseases; however, its role and the underlying mechanism in regulating diabetic cardiomyopathy remain unclear. In this study, we developed mouse models of diabetic cardiomyopathy using leptin receptor-deficient (db/db) mice and streptozocin-induced C57BL/6 mice. The diabetic cardiomyopathy model mice exhibited apparent structural damage in cardiac tissues and a significant increase in the expression of apoptosis-related proteins. Notably, we observed a significant decreased expression of GDF11 in the myocardium of mice with diabetic cardiomyopathy. Moreover, GDF11 cardiac-specific knock-in mice (transgenic mice) exhibited improved cardiac function and reduced apoptosis. Moreover, exogenous administration of GDF11 mitigated high glucose-induced cardiomyocyte apoptosis. Mechanistically, we demonstrated that GDF11 alleviated high glucose-induced cardiomyocytes apoptosis by inhibiting the activation of the alkylation repair homolog 5 (ALKBH5)-forkhead box group O3a (FOXO3)-cerebellar degeneration-related protein 1 transcript (CDR1as)/Hippo signaling pathway. Consequently, this novel mechanism effectively counteracted myocardial cell apoptosis, providing valuable insights into potential therapeutic strategies for clinical diabetic cardiomyopathy.

Growth differentiation factor-15 stimulates the synthesis of corticotropin-releasing factor in hypothalamic 4B cells.

Growth differentiation factor-15 (GDF15) is a stress-activated cytokine that regulates cell growth and inflammatory and stress responses. We previously reported the role and regulation of GDF15 in pituitary corticotrophs. Dexamethasone increases Gdf15 gene expression levels and production. GDF15 suppresses adrenocorticotropic hormone synthesis in pituitary corticotrophs and subsequently mediates the negative feedback effect of glucocorticoids. Here, we analyzed corticotropin-releasing factor (Crf) promoter activity in hypothalamic 4B cells transfected with promoter-driven luciferase reporter constructs. The effects of time and GDF15 concentration on Crf mRNA levels were analyzed using quantitative real-time polymerase chain reaction. Glial cell-derived neurotrophic factor family receptor α-like (GFRAL) protein is expressed in 4B cells. GDF15 increased Crf promoter activity and Crf mRNA levels in 4B cells. The protein kinase A and C pathways also contributed to the GDF15-induced increase in Crf gene expression. GDF15 stimulates GFRAL, subsequently increasing the phosphorylation of AKT, an extracellular signal-related kinase, and the cAMP response element-binding protein. Therefore, GDF15-dependent pathways may be involved in regulating Crf expression under stressful conditions in hypothalamic cells.

GDF11 as a friend or an enemy in the cancer biology?

The Growth and Differential Factor 11 (GDF11) is a recently discovered representative of Transforming Growth Factor ß superfamily. The highest expression of GDF11 is detected in the nervous system, bladder, seminal vesicles and muscles whereas the lowest in the testis, liver or breast. GDF11 role in physiology is still not clear. GDF11 is a crucial factor in embryogenesis, cell cycle control and apoptosis, inasmuch it mainly targets cell retain stemness features, managing to the cell differentiation and the maturation. GDF11 is entangled in lipid metabolism, inflammatory processes and aging. GDF11 is strongly related to carcinogenesis and its expression in tumors is intruded. GDF11 can promote cancer growth in the colon or inhibit the cell proliferation in breast cancer. The aberrated expression is probably allied with the impaired maturation. In this article we summarized an impact of GDF11 on the tumor cells and review the all attitudes connecting GDF11 with carcinogenesis.

Long-term intermittent fasting improves neurological function by promoting angiogenesis after cerebral ischemia via growth differentiation factor 11 signaling activation.

Intermittent fasting (IF), an alternative to caloric restriction, is a form of time restricted eating. IF conditioning has been suggested to have neuroprotective effects and potential long-term brain health benefits. But the mechanism underlying remains unclear. The present study focused on the cerebral angiogenesis effect of IF on ischemic rats. Using a rat middle cerebral artery occlusion model, we assessed neurological outcomes and various vascular parameters such as microvessel density (MVD), regional cerebral blood flow (rCBF), proliferation of endothelial cells (ECs), and functional vessels in the peri-infarct area. IF conditioning ameliorated the modified neurological severity score and adhesive removal test, increased MVD, and activated growth differentiation factor 11 (GDF11)/activin-like kinase 5 (ALK5) pathways in a time-dependent manner. In addition, long-term IF conditioning stimulated proliferation of ECs, promoted rCBF, and upregulated the total vessel surface area as well as the number of microvessel branch points through GDF11/ALK5 pathways. These data suggest that long-term IF conditioning improves neurological outcomes after cerebral ischemia, and that this positive effect is mediated partly by angiogenesis in the peri-infarct area and improvement of functional perfusion microvessels in part by activating the GDF11/ALK5 signaling pathway.

GDF11, a target of miR-32-5p, suppresses high-glucose-induced mitochondrial dysfunction and apoptosis in HK-2 cells through PI3K/AKT signaling activation.

PURPOSE: To investigate the role and underlying mechanism of GDF11 on diabetic nephropathy (DN)-related mitochondrial dysfunction and apoptosis. METHODS: A DN model of rats was established in this study. Human Kidney-2 (HK-2) cells were cultured under high-glucose (HG) condition with or without recombinant GDF11 (rGDF11). Mitochondrial morphology of HK-2 cells was analyzed by transmission electron microscope and MitoTracker Red CMXRos staining. Mitochondrial membrane potential (MMP) and ROS production were monitored using JC-1 assay kit and MitoSOX staining, respectively. Cell apoptosis was detected by TUNEL or flow cytometry assays. RESULTS: Herein, we observed that GDF11 was down-regulated in renal cortex and serum of DN rats, which was accompanied by renal mitochondrial morphological abnormalities. In line with the findings in vivo, HK-2 cells exposed to HG presented with mitochondrial morphological alterations and further apoptosis accompanied by GDF11 reduction. In addition, HG promoted a decrease in MMP while an increase in mitochondrial ROS production. Conversely, rGDF11 treatment significantly alleviated these HG-induced mitochondrial defects in HK-2 cells. Meanwhile, HK-2 cell apoptosis induced by HG was simultaneously suppressed by rGDF11. Mechanistically, the decreased levels of p-AKT induced by HG were attenuated after rGDF11 administration. Inhibition of the PI3K/AKT pathway resisted the effects of rGDF11 on the MMP and apoptosis of HK-2 cells. In addition, we identified that GDF11 is a target of miR-32-5p. Up-regulation of miR-32-5p could inhibit the expression of GDF11. CONCLUSION: rGDF11 treatment rescued HG-induced HK-2 cell mitochondrial dysfunction and apoptosis, which may be dependent on the activation of the PI3K/AKT pathway.

The hepatic effects of GDF11 on health and disease.

The growth differentiation factor 11 (GDF11), a member of the superfamily of the transforming growth factor ß, has gained relevance in the last few years due to its remarkable effects in cellular biology, particularly in the nervous system, skeletal muscle, the heart, and many epithelial tissues. Some controversies have been raised about this growth factor. Many of them have been related to technical factors but also the nature of the cellular target. In liver biology and pathobiology, the GDF11 has shown to be related in many molecular aspects, with a significant impact on the physiology and the initiation and progression of the natural history of liver diseases. GDF11 has been involved as a critical regulator in lipid homeostasis, which, as it is well known, is the first step in the progression of liver disease. However, also it has been reported that the GDF11 is involved in fibrosis, senescence, and cancer. Although there are some controversies, much of the literature indicates that GDF11 displays effects tending to solve or mitigate pathological states of the liver, with reasonable evidence of correlation with other organs or systems. To a large extent, the controversy, as mentioned, is due to technical problems, such as the specificity of GDF11 antibodies, confusion with its closer family member, myostatin, and the state of differentiation in the tissues. In the present work, we reviewed the specific effects of GDF11 in the biology and pathobiology of the liver as a potential and promising factor for therapeutic intervention shortly.

CircNUFIP2 overexpression induces GDF11 to ameliorate oxygen-glucose deprivation-induced hippocampal neuron cell apoptosis and oxidative stress after cerebral ischemia.

Background Previous data have indicated the regulation of circular RNA (circRNA) toward cerebral ischemia. This study aims to reveal the effects of circNUFIP2 on cerebral ischemia and the underlying mechanism. Methods Oxygen-glucose deprivation (OGD) hippocampal neuron (HT22) cell model and middle cerebral artery occlusion (MCAO) mouse model were used for this study. The expression of circRNA nuclear FMR1 interacting protein 2 (circNUFIP2), microRNA-1224-5p (miR-1224-5p) and growth differentiation factor 11 (GDF11) was detected by quantitative real-time polymerase-chain reaction. Protein expression was checked by Western blotting. The binding relationships among circNUFIP2, miR-1224-5p and GDF11 were identified by dual-luciferase reporter assay, RNA pull-down assay, and RNA immunoprecipitation assay. Cell proliferation and apoptosis were investigated by 5-Ethynyl-29-deoxyuridine and flow cytometry analysis, respectively. Results CircNUFIP2 and GDF11 expression were decreased, but miR-1224-5p was increased in OGD-treated HT22 cells when compared with their expression in control groups. OGD treatment inhibited HT22 cell proliferation but induced cell apoptosis and oxidative stress; however, these effects were attenuated after circNUFIP2 overexpression. Also, circNUFIP2 upregulation assuaged the cerebral infarction of MCAO mice. Besides, circNUFIP2 bound to miR-1224-5p and mediated OGD-induced HT22 cell damage through miR-1224-5p. Meanwhile, knockdown of GDF11, a target gene of miR-1224-5p, relieved miR-1224-5p depletion-caused effects in OGD-treated HT22 cells. Furthermore, circNUFIP2 regulated GDF11 expression by interacting with miR-1224-5p. Conclusion CircNUFIP2 overexpression protected neuron cells against cerebral ischemia-induced damage, at least in part, by the miR-1224-5p/GDF11 pathway, providing a possible target for the therapy of cerebral ischemic stroke.

Growth differentiation factor 11: A proangiogenic drug as a potential antiaging regulating molecule.

Organs and tissues are subjected to numerous alterations during aging, as a result of complex biochemical changes. Aging is certainly associated with the accumulation of "antiaging" and "proaging" factors in the systemic circulation. The effects of young blood on rejuvenation of regenerative capacity suggest the existence of multiple "proyouthful" factors, such as growth differentiation factor 11 (GDF11), in the young blood of animals. GDF11 is a member of the transforming growth factor beta (TGFß) superfamily of cytokines, and appears to be a critical rejuvenation factor in aging organs. In the context of aging, GDF11 promotes vascular and neural plasticity of the central nervous system. Parabiosis, the surgical linking of circulations between old and young mice, was employed to identify GDF11 as an antihypertrophic factor that appears to rejuvenate the aging murine heart. Current theories suggest that GDF11 in young blood has beneficial effects on cognitive and cardiovascular functions and wound healing. The cellular mechanisms of GDF11 in cardiovascular, neurological, skin and skeletal muscle diseases are not clearly defined, but evidence indicates that it may function as a proneurogenic and proangiogenic drug. GDF11 binds and activates specific receptor complexes, which transmit signals by two procedures: the TGFß-Smad pathway and the bone morphogenic protein (BMP)-Smad pathway. GDF11 is perhaps only the first in a series of circulating molecules that will be found to influence the aging of different tissues, and it may be a potential candidate for therapeutic intervention against angiogenesis-related disorders.

Spermidine inhibits high glucose-induced endoplasmic reticulum stress in HT22 cells by upregulation of growth differentiation factor 11.

Hyperglycemia-induced neuronal endoplasmic reticulum (ER) stress is particularly important for the pathogenesis of diabetic encephalopathy. Spermidine (Spd) has neuroprotection in several nervous system diseases. Our current study to explore the potential protective role of Spd in hyperglycemia-induced neuronal ER stress and the underlying mechanisms. HT22 cells were treated with high glucose (HG) to establish an in-vitro model of hyperglycemia toxicity. The HT22 cells' activity was tested by cell counting kit-8 assay. RNA interference technology was used to silence the expression of growth differentiation factor 11 (GDF11) in HT22 cells. The GDF11 expression levels of mRNA were assessed using reverse transcription-PCR (RT-PCR). Western blotting analysis was applied to evaluate the expressions of GRP78 and cleaved caspase-12. Spd markedly abolished HG-exerted decline in cell viability as well as upregulations of GRP78 and cleaved caspase-12 in HT22 cells, indicating the protection of Spd against HG-induced neurotoxicity and ER stress. Furthermore, we showed that Spd upregulated the expression of GDF11 in HG-exposed HT22 cells. While, silenced GDF11 expression by RNA interference reversed the protective effects of Spd on HG-elicited neurotoxicity and ER stress in HT22 cells. These results indicated that Spd prevents HG-induced neurotoxicity and ER stress through upregulation of GDF11. Our findings identify Spd as a potential treatment for diabetic encephalopathy as well as ER stress-related neurologic diseases.

Pathophysiological levels of GDF11 activate Smad2/Smad3 signaling and induce muscle atrophy in human iPSC-derived myocytes.

Skeletal muscle mass is negatively regulated by several TGF-ß superfamily members. Myostatin (MSTN) is the most prominent negative regulator of muscle mass. Recent studies show that in addition to MSTN, GDF11, which shares a high sequence identity with MSTN, induces muscle atrophy in vitro and in vivo at supraphysiological levels, whereas controversy regarding its roles exists. Furthermore, higher circulating GDF11 levels associate with frailty in humans. On the other hand, little is known about the effect of pathophysiological levels of GDF11 on muscle atrophy. Here we seek to determine whether pathophysiological levels of GDF11 are sufficient to activate Smad2/Smad3 signaling and induce muscle atrophy using human iPSC-derived myocytes (hiPSC myocytes). We first show that incubating hiPSC myocytes with pathophysiological concentrations of GDF11 significantly reduces myocyte diameters. We next demonstrate that pathophysiological levels of GDF11 are sufficient to activate Smad2/3 signaling. Finally, we show that pathophysiological levels of GDF11 are capable of inducing the expression of Atrogin-1, an atrophy-promoting E3 ubiquitin ligase and that FOXO1 blockage reverses the GDF11-induced Atrogin-1 expression and atrophic phenotype. Collectively, our results suggest that GDF11 induces skeletal muscle atrophy at the pathophysiological levels through the GDF11-FOXO1 axis.

Follistatin dysregulation impaired trophoblast biological functions by GDF11-Smad2/3 axis in preeclampsia placentas.

INTRODUCTION: Preeclampsia (PE) is one of the main causes of maternal, fetal, and neonatal mortality. So far, the underlying mechanism of this pregnancy-specific syndrome remains unelucidated. The expression of Follistatin (FST) decreased in maternal serum (especially early onset severe PE) and placental trophoblasts of PE patients. However, whether FST-deficiency in preeclamptic placentas alters trophoblast function remains to be determined. METHODS: Trophoblast cell lines were cultured in vitro and LV3 short hairpin RNA (shRNA) was used to silence FST. Growth and differentiation factor 11 (GDF11) expression level in placentas and serum were detected by immunohistochemistry and enzyme-linked immune-sorbent assay, respectively. To verify the effect of reduced FST expression on trophoblasts, microRNA-24-3p, which was predicted to target the 3'-untranslated region (3'-UTR) of FST, was screened out, and miR-24-3p mimic, inhibitor was used to regulate FST expression in trophoblasts. RESULTS: Downregulation of FST significantly enhanced the apoptosis and impaired migration and invasion of trophoblast. Reduced FST caused the upregulation of GDF11 in trophoblasts. Interestingly, GDF11 reduced in preeclamptic placental microvascular endothelial cells. Dysregulation of FST-GDF11-Smad2/3 signaling pathway, leading to increased apoptosis of trophoblast. Expression levels of miR-24-3p, was significantly elevated in preeclamptic placentas. Trophoblast cells transfected with miR-24-3p mimics displayed impaired migration and invasion and increased apoptosis. Treated by miR-24-3p inhibitor, trophoblast cells exhibited rescued function. DISCUSSION: FST-deficiency impaired trophoblast function by upregulating GDF11 levels in trophoblasts. The regulation of FST-GDF11-Smad2/3 axis by microRNAs mimic or inhibitor may be critical to trophoblast function regulation and helps to deepen our understanding of the molecular mechanism of PE.

Effects of Soy Milk in Conjunction With Resistance Training on Physical Performance and Skeletal Muscle Regulatory Markers in Older Men.

Purpose: We aimed to determine the effects of 12 weeks of soy milk consumption combined with resistance training (RT) on body composition, physical performance, and skeletal muscle regulatory markers in older men. Methods: In this randomized clinical trial study, 60 healthy elderly men (age = 65.63 ± 3.16 years) were randomly assigned to four groups: resistance training (RT; n = 15), soy milk consumption (SMC; n = 15), resistance training + soy milk (RSM; n = 15), and control (CON; n = 15) groups. The study was double-blind for the soy milk/placebo. Participants in RT and RSM groups performed resistance training (3 times/week) for 12 weeks. Participants in the SMC and RSM groups consumed 240 mL of soy milk daily. Body composition [body mass (BM), body fat percent (BFP), waist-hip ratio (WHR), and fat mass (FM)], physical performance [upper body strength (UBS), lower body strength (LBS), VO2max, upper anaerobic power, lower anaerobic power, and handgrip strength], and serum markers [follistatin, myostatin, myostatin-follistatin ratio (MFR), and growth and differentiation factor 11 (GDF11)] were evaluated before and after interventions. Results: All 3 interventions significantly (p < 0.05) increased serum follistatin concentrations (RT = 1.7%, SMC = 2.9%, RSM = 7.8%) and decreased serum myostatin (RT = -1.3% SMC = -5.4%, RSM = -0.5%) and GDF11 concentrations (RT = -1.4%, SMC = -1.4%, RSM = -9.0%), and MFR (RT = -2.6%, SMC = -3.2%, RSM = -12%). In addition, we observed significant reduction in all 3 intervention groups in BFP (RT = -3.6%, SMC = -1.4%, RSM = -6.0%), WHR (RT = -2.2%, SMC = -2.1%, RSM = -4.3%), and FM (RT = -9.6%, SMC = -3.8%, RSM = -11.0%). Moreover, results found significant increase only in RT and RSM groups for muscle mass (RT = 3.8% and RSM = 11.8%), UBS (RT = 10.9% and RSM = 21.8%), LBS (RT = 4.3% and RSM = 7.8%), upper anaerobic power (RT = 7.8% and RSM = 10.3%), and lower anaerobic power (RT = 4.6% and RSM = 8.9%). Handgrip strength were significantly increased in all 3 intervention groups (RT = 7.0%, SMC = 6.9%, RSM = 43.0%). VO2max significantly increased only in RSM (1.7%) after 12 weeks of intervention. Additionally, significant differences were observed between the changes for all variables in the RSM group compared to RT, SMC, and CON groups (p < 0.05). Conclusions: There were synergistic effects of soy milk and RT for skeletal muscle regulatory markers, body composition, and physical performance. Results of the present study support the importance of soy milk in conjunction with RT for older men.

Multifaceted Benefits of GDF11 Treatment in Spinal Cord Injury: In Vitro and In Vivo Studies.

Traumatic spinal cord injury (SCI) initiates a series of cellular and molecular events that include both primary and secondary injury cascades. This secondary cascade provides opportunities for the delivery of therapeutic intervention. Growth differentiation factor 11 (GDF11), a member of the transforming growth factor-ß (TGF-ß) superfamily, regulates various biological processes in mammals. The effects of GDF11 in the nervous system were not fully elucidated. Here, we perform extensive in vitro and in vivo studies to unravel the effects of GDF11 on spinal cord after injury. In vitro culture studies showed that GDF11 increased the survival of both neuronal and oligodendroglial cells but decreased microglial cells. In stressed cultures, GDF11 effectively inhibited LPS stimulation and also protected neurons from ischemic damage. Intravenous GDF11 administration to rat after eliciting SCI significantly improved hindlimb functional restoration of SCI rats. Reduced neuronal connectivity was evident at 6 weeks post-injury and these deficits were markedly attenuated by GDF11 treatment. Furthermore, SCI-associated oligodendroglial alteration were more preserved by GDF11 treatment. Taken together, GDF11 infusion via intravenous route to SCI rats is beneficial, facilitating its therapeutic application in the future.

GDF-11 Protects the Traumatically Injured Spinal Cord by Suppressing Pyroptosis and Necroptosis via TFE3-Mediated Autophagy Augmentation.

Spinal cord injury (SCI) refers to a major worldwide cause of accidental death and disability. However, the complexity of the pathophysiological mechanism can result in less-effective clinical treatment. Growth differentiation factor 11 (GDF-11), an antiageing factor, was reported to affect the development of neurogenesis and exert a neuroprotective effect after cerebral ischaemic injury. The present work is aimed at investigating the influence of GDF-11 on functional recovery following SCI, in addition to the potential mechanisms involved. We employed a mouse model of spinal cord contusion injury and assessed functional outcomes via the Basso Mouse Scale and footprint analysis following SCI. Using western blot assays and immunofluorescence, we analysed the levels of pyroptosis, autophagy, necroptosis, and molecules related to the AMPK-TRPML1-calcineurin signalling pathway. The results showed that GDF-11 noticeably optimized function-related recovery, increased autophagy, inhibited pyroptosis, and alleviated necroptosis following SCI. Furthermore, the conducive influences exerted by GDF-11 were reversed with the application of 3-methyladenine (3MA), an autophagy suppressor, indicating that autophagy critically impacted the therapeutically related benefits of GDF-11 on recovery after SCI. In the mechanistic study described herein, GDF-11 stimulated autophagy improvement and subsequently inhibited pyroptosis and necroptosis, which were suggested to be mediated by TFE3; this effect resulted from the activity of TFE3 through the AMPK-TRPML1-calcineurin signalling cascade. Together, GDF-11 protects the injured spinal cord by suppressing pyroptosis and necroptosis via TFE3-mediated autophagy augmentation and is a potential agent for SCI therapy.

Dynamic extrinsic pacing of the HOX clock in human axial progenitors controls motor neuron subtype specification.

Rostro-caudal patterning of vertebrates depends on the temporally progressive activation of HOX genes within axial stem cells that fuel axial embryo elongation. Whether the pace of sequential activation of HOX genes, the 'HOX clock', is controlled by intrinsic chromatin-based timing mechanisms or by temporal changes in extrinsic cues remains unclear. Here, we studied HOX clock pacing in human pluripotent stem cell-derived axial progenitors differentiating into diverse spinal cord motor neuron subtypes. We show that the progressive activation of caudal HOX genes is controlled by a dynamic increase in FGF signaling. Blocking the FGF pathway stalled induction of HOX genes, while a precocious increase of FGF, alone or with GDF11 ligand, accelerated the HOX clock. Cells differentiated under accelerated HOX induction generated appropriate posterior motor neuron subtypes found along the human embryonic spinal cord. The pacing of the HOX clock is thus dynamically regulated by exposure to secreted cues. Its manipulation by extrinsic factors provides synchronized access to multiple human neuronal subtypes of distinct rostro-caudal identities for basic and translational applications.This article has an associated 'The people behind the papers' interview.

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.

GDF11 inhibits cardiomyocyte pyroptosis and exerts cardioprotection in acute myocardial infarction mice by upregulation of transcription factor HOXA3.

NLRP3 (Nucleotide-binding oligomerization domain-like receptor pyrin domain-containing 3) inflammasome-mediated cardiomyocytes pyroptosis plays a crucial part in progression of acute myocardial infarction (MI). GDF11 (Growth Differentiation Factor 11) has been reported to generate cytoprotective effects in phylogenesis and multiple diseases, but the mechanism that GDF11 contributes to cardioprotection of MI and cardiomyocytes pyroptosis remains poorly understood. In our study, we first determined that GDF11 was abnormally downregulated in the heart tissue of MI mice and hypoxic cardiomyocytes. Moreover, AAV9-GDF11 markedly alleviated heart function in MI mice. Meanwhile, GDF11 overexpression also decreased the pyroptosis of hypoxic cardiomyocytes. PROMO and JASPAR prediction software found that transcription factor HOXA3 was predicted as an important regulator of NLRP3, and was confirmed by ChIP assay. Further analysis identifying GDF11 promoted the Smad2/3 pathway resulted in HOXA3 overexpression. Taken together, our study implies that GDF11 prevents cardiomyocytes pyroptosis via HOXA3/NLRP3 signaling pathway in MI mice.

Exogenous GDF11, but not GDF8, reduces body weight and improves glucose homeostasis in mice.

Insulin resistance is associated with aging in mice and humans. We have previously shown that administration of recombinant GDF11 (rGDF11) to aged mice alters aging phenotypes in the brain, skeletal muscle, and heart. While the closely related protein GDF8 has a role in metabolism, limited data are available on the potential metabolic effects of GDF11 or GDF8 in aging. To determine the metabolic effects of these two ligands, we administered rGDF11 or rGDF8 protein to young or aged mice fed a standard chow diet, short-term high-fat diet (HFD), or long-term HFD. Under nearly all of these diet conditions, administration of exogenous rGDF11 reduced body weight by 3-17% and significantly improved glucose tolerance in aged mice fed a chow (~30% vs. saline) or HF (~50% vs. saline) diet and young mice fed a HFD (~30%). On the other hand, exogenous rGDF8 showed signifcantly lesser effect or no effect at all on glucose tolerance compared to rGDF11, consistent with data demonstrating that GFD11 is a more potent signaling ligand than GDF8. Collectively, our results show that administration of exogenous rGDF11, but not rGDF8, can reduce diet-induced weight gain and improve metabolic homeostasis.

Positive Effects of a Young Systemic Environment and High Growth Differentiation Factor 11 Levels on Chondrocyte Proliferation and Cartilage Matrix Synthesis in Old Mice.

OBJECTIVE: To investigate the effects of a young systemic environment and growth differentiation factor 11 (GDF-11) on aging cartilage. METHODS: A heterochronic parabiosis model (2-month-old mouse and 12-month-old mouse [Y/O]), an isochronic parabiosis model (12-month-old mouse and 12-month-old mouse [O/O]), and 12-month-old mice alone (O) were evaluated. Knee joints and chondrocytes from old mice were examined by radiography, histology, cell proliferation assays, immunohistochemistry, Western blotting, and quantitative reverse transcriptase-polymerase chain reaction 16 weeks after parabiosis surgery. GDF-11 was injected into 12-month-old mouse joints daily for 16 weeks. Cartilage degeneration, cell proliferation, and osteoarthritis-related gene expression were evaluated. RESULTS: Osteoarthritis Research Society International scores in old mice were significantly lower in the Y/O group than in the O/O and O groups (both P < 0.05). The percentage of 5-ethynyl-2'-deoxyuridine-positive chondrocytes in old mice was significantly higher in the Y/O group than in the other groups (P < 0.05). Type II collagen (CII) and SOX9 messenger RNA levels differed in cartilage from old mice in the Y/O group compared to the O/O and O groups (both P < 0.05). RUNX-2, CX, and matrix metalloproteinase 13 levels were significantly lower in cartilage from old mice in the Y/O group compared to the O/O and O groups (both P < 0.05). Similar results were obtained for protein expression levels and after GDF-11 treatment in vitro and in vivo. Phosphorylated Smad2/3 (pSmad2/3) levels were higher in the recombinant GDF-11-treated group than in the control group. CONCLUSION: A young systemic environment promotes chondrocyte proliferation and cartilage matrix synthesis in old mice. GDF-11, a "young factor," contributes to these effects through the up-regulation of pSmad2/3.