GDF11 is increased in patients with aplastic anemia

Growth differentiation factor-11 upregulates matrix metalloproteinase 2 expression by inducing Snail in human extravillous trophoblast cells

The human extravillous trophoblast (EVT) cell invasion is an important process during placentation. Although the placenta is normal tissue, the EVT cells exhibit some features common to cancer cells, including high migratory and invasive properties. Snail and Slug are transcription factors that mediate the epithelial-mesenchymal transition (EMT), a crucial event for cancer cell migration and invasion. It has been shown that GDF-11-induced matrix metalloproteinase 2 (MMP2) expression is required for EVT cell invasion. Whether GDF-11 can regulate Snail and Slug expression in human EVT cells remains unknown. If it does, the involvement of Snail and Slug in GDF-11-induced MMP2 expression and EVT cell invasion must also be defined. In the present study, using the immortalized human EVT cell line, HTR-8/SVneo, and primary cultures of human EVT cells as experimental models, our results show that GDF-11 upregulates Snail and Slug expression. ALK4 and ALK5 mediate the stimulatory effects of GDF-11 on Snail and Slug expression. In addition, we demonstrate that SMAD2 and SMAD3 are required for the GDF-11-upregulated Snail expression, while only SMAD3 is involved in GDF-11-induced Slug expression. Moreover, our results reveal that Snail mediates GDF-11-induced MMP2 expression and cell invasion but not Slug. This study increases our understanding of the biological function of GDF-11 in human EVT cells and provides a novel mechanism for regulating MMP2 and EVT cell invasion.

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.

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

BACKGROUND

The 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.

METHODS

Two 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.

RESULTS

Our 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.

CONCLUSIONS

This 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. Video Abstract.

Growth differentiation factor 11: A new hope for the treatment of cardiovascular diseases

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor-β superfamily that has garnered significant attention due to its anti-cardiac aging properties. Many studies have revealed that GDF11 plays an indispensable role in the onset of cardiovascular diseases (CVDs). Consequently, it has emerged as a potential target and novel therapeutic agent for CVD treatment. However, currently, no literature reviews comprehensively summarize the research on GDF11 in the context of CVDs. Therefore, herein, we comprehensively described GDF11's structure, function, and signaling in various tissues. Furthermore, we focused on the latest findings concerning its involvement in CVD development and its potential for clinical translation as a CVD treatment. We aim to provide a theoretical basis for the prospects and future research directions of the GDF11 application regarding CVDs.

GDF-11 promotes human trophoblast cell invasion by increasing ID2-mediated MMP2 expression

BACKGROUND

Growth differentiation factor-11 (GDF-11), also known as bone morphogenetic protein-11, belongs to the transforming growth factor-beta superfamily. GDF-11 was first identified as an important regulator during embryonic development. Increasing evidence has demonstrated that GDF-11 regulates the development of various organs and its aberrant expressions are associated with the risk of cardiovascular diseases and cancers. Extravillous trophoblast (EVT) cells invasion is a critical event for placenta development and needs to be finely regulated. However, to date, the biological function of GDF-11 in the human EVT cells remains unknown.

METHODS

HTR-8/SVneo, a human EVT cell line, and primary cultures of human EVT cells were used to examine the effect of GDF-11 on matrix metalloproteinase 2 (MMP2) expression. Matrigel-coated transwell invasion assay was used to examine cell invasiveness. A series of in vitro experiments were applied to explore the underlying mechanisms that mediate the effect of GDF-11 on MMP2 expression and cell invasion.

RESULTS

Treatment with GDF-11 stimulates MMP2 expression, in the HTR-8/SVneo and primary human EVT cells. Using a pharmacological inhibitor and siRNA-mediated knockdown approaches, our results demonstrated that the stimulatory effect of GDF-11 on MMP2 expression was mediated by the ALK4/5-SMAD2/3 signaling pathways. In addition, the expression of inhibitor of DNA-binding protein 2 (ID2) was upregulated by GDF-11 and that was required for the GDF-11-stimulated MMP2 expression and EVT cell invasion.

CONCLUSIONS

These findings discover a new biological function and underlying molecular mechanisms of GDF-11 in the regulation of human EVT cell invasion. Video Abstract.

Growth differentiation factor-11 downregulates steroidogenic acute regulatory protein expression through ALK5-mediated SMAD3 signaling pathway in human granulosa-lutein cells

BACKGROUND

Growth differentiation factor-11 (GDF-11) belongs to the transforming growth factor-β (TGF-β) superfamily. To date, the expression of GDF-11 in the ovary and its role in regulating ovarian function are completely unknown. Ovarian granulosa cell-mediated steroidogenesis plays a pivotal role in maintaining normal female reproductive function. GDF-11 and GDF-8 share high sequence similarity and exhibit many similar features and functions. Steroidogenic acute regulatory protein (StAR) regulates the rate-limiting step in steroidogenesis and its expression can be downregulated by GDF-8. Polycystic ovary syndrome (PCOS) is the most common cause of female infertility. The expression levels of GDF-8 are upregulated in the human follicular fluid and granulosa-lutein (hGL) cells of PCOS patients. However, whether similar results can be observed for the GDF-11 needs to be determined.

METHODS

The effect of GDF-11 on StAR expression and the underlying molecular mechanisms were explored by a series of in vitro experiments in a primary culture of hGL cells obtained from patients undergoing in vitro fertilization (IVF) treatment. Human follicular fluid samples were obtained from 36 non-PCOS patients and 36 PCOS patients. GDF-11 levels in follicular fluid were measured by ELISA.

RESULTS

GDF-11 downregulates StAR expression, whereas the expression levels of the P450 side-chain cleavage enzyme (P450scc) and 3β-hydroxysteroid dehydrogenase (3β-HSD) are not affected by GDF-11 in hGL cells. Using pharmacological inhibitors and a siRNA-mediated approach, we reveal that ALK5 but not ALK4 mediates the suppressive effect of GDF-11 on StAR expression. Although GDF-11 activates both SMAD2 and SMAD3 signaling pathways, only SMAD3 is involved in the GDF-11-induced downregulation of StAR expression. In addition, we show that SMAD1/5/8, ERK1/2, and PI3K/AKT signaling pathways are not activated by GDF-11 in hGL cells. RT-qPCR and ELISA detect GDF-11 mRNA expression in hGL cells and GDF-11 protein expression in human follicular fluid, respectively. Interestingly, unlike GDF-8, the expression levels of GDF-11 are not varied in hGL cells and follicular fluid between non-PCOS and PCOS patients.

CONCLUSIONS

This study increases the understanding of the biological function of GDF-11 and provides important insights into the regulation of ovarian steroidogenesis.

Growth differentiation factor 11: a "rejuvenation factor" involved in regulation of age-related diseases?

Growth differentiation factor 11 (GDF11), a member of the transforming growth factor β superfamily of cytokines, is a critical rejuvenation factor in aging cells. GDF11 improves neurodegenerative and neurovascular disease outcomes, increases skeletal muscle volume, and enhances muscle strength. Its wide-ranging biological effects may include the reversal of senescence in clinical applications, as well as the ability to reverse age-related pathological changes and regulate organ regeneration after injury. Nevertheless, recent data have led to controversy regarding the functional roles of GDF11, because the underlying mechanisms were not clearly established in previous studies. In this review, we examine the literature regarding GDF11 in age-related diseases and discuss potential mechanisms underlying the effects of GDF11 in regulation of age-related diseases.

miR-144-3p Suppresses Osteogenic Differentiation of BMSCs from Patients with Aplastic Anemia through Repression of TET2

Reduced osteogenic capacity of bone marrow mesenchymal stem cells (BMSCs) has been causally linked to the development of aplastic anemia. In this work, we aimed to identify novel microRNAs (miRNAs) that participate in the regulation of differentiation of BMSCs from patients with aplastic anemia. We show that miR-144-3p is significantly upregulated in BMSCs from patients with aplastic anemia relative to control equivalents. Depletion of miR-144-3p significantly enhances osteogenic differentiation of BMSCs from patients with aplastic anemia after culturing in osteogenesis-inducing medium. Conversely, overexpression of miR-144-3p blocks osteogenic differentiation of BMSCs. Mechanistically, miR-144-3p negatively regulates the expression of ten-eleven translocation 2 (TET2) in BMSCs. Reduced TET2 expression is associated with a significant decrease in global 5-hydroxymethyl-cytosine (5hmC) levels and osteogenic gene expression. Knockdown of miR-144-3p elevates the expression of TET2 and total 5hmC levels in BMSCs. Silencing of TET2 inhibits the osteogenic differentiation of BMSCs. Overexpression of TET2 reverses miR-144-3p-mediated inhibition of osteogenesis. In addition, there is a significant negative correlation between the expression of miR-144-3p and TET2 in BMSCs from patients with aplastic anemia. Overall, miR-144-3p impairs the osteogenic capacity of BMSCs from patients with aplastic anemia through repression of TET2. Therefore, the targeting of miR-144-3p may be a therapeutic strategy against aplastic anemia.

Circulating factors in young blood as potential therapeutic agents for age-related neurodegenerative and neurovascular diseases

Recent animal studies on heterochronic parabiosis (a technique combining the blood circulation of two animals) have revealed that young blood has a powerful rejuvenating effect on brain aging. Circulating factors, especially growth differentiation factor 11 (GDF11) and C-C motif chemokine 11 (CCL11), may play a key role in this effect, which inspires hope for novel approaches to treating age-related cerebral diseases in humans, such as neurodegenerative and neurovascular diseases. Recently, attempts have begun to translate these astonishing and exciting findings from mice to humans and from bench to bedside. However, increasing reports have shown contradictory data, questioning the capacity of these circulating factors to reverse age-related brain dysfunction. In this review, we summarize the current research on the role of young blood, as well as the circulating factors GDF11 and CCL11, in the aging brain and age-related cerebral diseases. We highlight recent controversies, discuss related challenges and provide a future outlook.