Concise review: growth differentiation factor 15 in pathology: a clinical role?

Growth Differentiation Factor-15 and Clinical Outcomes in Lower Extremity Artery Disease

AIM

Lower extremity artery disease (LEAD) is an increasingly common health problem that is associated with high mortality due to thrombotic and bleeding events. Growth differentiation factor-15 (GDF15), a stress-response cytokine belonging to the transforming growth factor-beta superfamily, is associated with cardiovascular disease and its outcomes. The aim of the present study was to examine the effect of serum GDF15 levels on clinical outcomes in patients with LEAD.

METHODS

We measured serum GDF15 levels in 200 patients with LEAD before their initial endovascular therapy. The primary endpoint was the all-cause mortality rate. The secondary endpoints, on the other hand, were thrombotic and bleeding events, such as cerebral infarction, acute coronary syndrome, acute limb ischemia, and Bleeding Academic Research Consortium types 3 and 5.

RESULTS

The serum GDF15 levels increased with advancing Fontaine class. Kaplan-Meier analysis revealed that the high-GDF15 group (≥ 2,275 pg/mL) had higher rates of all-cause deaths and thrombotic and bleeding events than the low-GDF15 group (＜2,275 pg/mL). Multivariate Cox proportional-hazards regression analysis revealed that GDF15 was an independent predictor of all-cause mortality and thrombotic and bleeding events after adjusting for confounding risk factors. When the ABC-AF-bleeding score was substituted for GDF15, similar results were obtained.

CONCLUSION

Serum GDF15 levels were associated with all-cause mortality and thrombotic and bleeding events in patients with LEAD. Serum GDF15 is a potentially useful marker of clinical outcomes, specifically for tracking thrombotic and bleeding events in patients with LEAD.

Heart Failure with Mildly Reduced Ejection Fraction-A Phenotype Waiting to Be Explored

Heart failure (HF) presents a significant global health challenge recognised by frequent hospitalisation and high mortality rates. The assessment of left ventricular (LV) ejection fraction (EF) plays a crucial role in diagnosing and predicting outcomes in HF, leading to its classification into preserved (HFpEF), reduced (HFrEF), and mildly reduced (HFmrEF) EF. HFmrEF shares features of both HFrEF and HFpEF but also exhibits distinct characteristics. Despite advancements, managing HFmrEF remains challenging due to its diverse presentation. Large-scale studies are needed to identify the predictors of clinical outcomes and treatment responses. Utilising biomarkers for phenotyping holds the potential for discovering new treatment targets. Given the uncertainty surrounding optimal management, individualised approaches are imperative for HFmrEF patients. This chapter examines HFmrEF, discusses the rationale for its re-classification, and elucidates HFmrEF's key attributes. Furthermore, it provides a comprehensive review of current treatment strategies for HFmrEF patients.

Growth differentiation factor-15 serum concentrations reflect disease severity and anemia in patients with inflammatory bowel disease

BACKGROUND

Population of patients with inflammatory bowel disease (IBD) is burdened by various extraintestinal manifestations which substantially contribute to greater morbidity and mortality. Growth-differentiation factor-15 (GDF-15) is often over-expressed under stress conditions, such as inflammation, malignancies, heart failure, myocardial ischemia, and many others.

AIM

To explore the association between GDF-15 and IBD as serum concentrations of GDF-15 were shown to be an independent predictor of poor outcomes in multiple diseases. An additional aim was to determine possible associations between GDF-15 and multiple clinical, anthropometric and laboratory parameters in patients with IBD.

METHODS

This cross-sectional study included 90 adult patients diagnosed with IBD, encompassing both Crohn's disease (CD) and ulcerative colitis (UC), and 67 healthy age- and sex-matched controls. All patients underwent an extensive workup, including colonoscopy with subsequent histopathological analysis. Disease activity was assessed by two independent gastroenterology consultants specialized in IBD, employing well-established clinical and endoscopic scoring systems. GDF-15 serum concentrations were determined following an overnight fasting, using electrochemiluminescence immunoassay.

RESULTS

In patients with IBD, serum GDF-15 concentrations were significantly higher in comparison to the healthy controls [800 (512-1154) pg/mL vs 412 (407-424) pg/mL, P < 0.001], whereas no difference in GDF-15 was found between patients with CD and UC [807 (554-1451) pg/mL vs 790 (509-956) pg/mL, P = 0.324]. Moreover, multiple linear regression analysis showed that GDF-15 levels predict CD and UC severity independent of age, sex, and C-reactive protein levels (P = 0.016 and P = 0.049, respectively). Finally, an association between GDF-15 and indices of anemia was established. Specifically, negative correlations were found between GDF-15 and serum iron levels (r = -0.248, P = 0.021), as well as GDF-15 and hemoglobin (r = -0.351, P = 0.021). Accordingly, in comparison to IBD patients with normal hemoglobin levels, GDF-15 serum levels were higher in patients with anemia (1256 (502-2100) pg/mL vs 444 (412-795) pg/mL, P < 0.001).

CONCLUSION

For the first time, we demonstrated that serum concentrations of GDF-15 are elevated in patients with IBD in comparison to healthy controls, and the results imply that GDF-15 might be involved in IBD pathophysiology. Yet, it remains elusive whether GDF-15 could serve as a prognostic indicator in these patients.

Advanced Technologies in Radiation Research

The U.S. Government is committed to maintaining a robust research program that supports a portfolio of scientific experts who are investigating the biological effects of radiation exposure. On August 17 and 18, 2023, the Radiation and Nuclear Countermeasures Program, within the National Institute of Allergy and Infectious Diseases, National Institutes of Health (NIH), partnered with the National Cancer Institute, NIH, the National Aeronautics and Space Administration, and the Radiation Injury Treatment Network to convene a workshop titled, Advanced Technologies in Radiation Research (ATRR), which focused on the use of advanced technologies under development or in current use to accelerate radiation research. This meeting report provides a comprehensive overview of the research presented at the workshop, which included an assembly of subject matter experts from government, industry, and academia. Topics discussed during the workshop included assessments of acute and delayed effects of radiation exposure using modalities such as clustered regularly interspaced short palindromic repeats (CRISPR) - based gene editing, tissue chips, advanced computing, artificial intelligence, and immersive imaging techniques. These approaches are being applied to develop products to diagnose and treat radiation injury to the bone marrow, skin, lung, and gastrointestinal tract, among other tissues. The overarching goal of the workshop was to provide an opportunity for the radiation research community to come together to assess the technological landscape through sharing of data, methodologies, and challenges, followed by a guided discussion with all participants. Ultimately, the organizers hope that the radiation research community will benefit from the workshop and seek solutions to scientific questions that remain unaddressed. Understanding existing research gaps and harnessing new or re-imagined tools and methods will allow for the design of studies to advance medical products along the critical path to U.S. Food and Drug Administration approval.

Exploring the Role of GDF-15 in Inflammatory Bowel Disease: A Case-Controlled Study Comparing Crohn's Disease and Ulcerative Colitis with Non-Inflammatory Controls

Inflammatory bowel disease, encompassing Crohn's disease and ulcerative colitis, is a persistent immune-mediated inflammatory gastrointestinal disease. This study investigates the role of growth differentiation factor 15 in severe IBD cases, aiming to identify a reliable parameter to assess disease severity and monitor activity. We analyzed plasma samples from 100 patients undergoing biologic therapy for severe IBD and 50 control subjects. Our analysis included evaluations of GDF-15 levels, inflammatory markers, and clinical features. We employed statistical methods such as the Mann-Whitney U test, ANOVA, and Spearman's correlation for an in-depth analysis. Our results demonstrated consistently higher GDF-15 levels in patients with both Crohn's disease and ulcerative colitis compared to the control group, irrespective of the biologic treatment received. The correlation analysis indicated significant relationships between GDF-15 levels, patient age, fibrinogen, and IL-6 levels. This study positions GDF-15 as a promising biomarker for severe IBD, with notable correlations with age and inflammatory markers. These findings underscore GDF-15's potential in enhancing disease monitoring and management strategies in an IBD context and encourage further research to clarify GDF-15's role in the IBD pathophysiology.

Association of growth and differentiation factor-15 with coronary artery calcium score and ankle-brachial index in a middle-aged and elderly Caucasian population sample free of manifest cardiovascular disease

Growth and differentiation factor-15 (GDF-15) is a stress-associated cytokine of the transforming growth factor-β superfamily. The inflammatory and angiogenic effects of GDF-15 in atherosclerosis are controversial, and its correlation with the long asymptomatic phase of the disease is not well understood. Coronary artery calcium score (CACS) and ankle-brachial index (ABI) are sensitive markers of subclinical atherosclerosis. To date, only a few studies have examined the impact of GDF-15 on coronary artery calcification, and the association between GDF-15 and ABI has not been evaluated. Therefore, we aimed to investigate the possible relationship between serum GDF-15 concentrations and CACS and ABI in a Caucasian population sample of middle-aged (35-65 years) and elderly (> 65 years) people. In addition to recording demographic and anthropometric characteristics, atherosclerotic risk factors, and laboratory tests including serum HDL-cholesterol, LDL-cholesterol, hemoglobin A1c (HbA1c), high-sensitivity C-reactive protein, and N-terminal pro-B-type natriuretic peptide (NT-proBNP); GDF-15 level, cardiac computed tomography, and ABI measurements were also performed. A total of 269 asymptomatic individuals (men, n = 125; median age, 61.5 [IQR, 12.7] years) formed the basis of this study. Participants were divided into two groups according to their age (middle-aged, n = 175 and elderly, n = 94). Hypertension and diabetes mellitus were significantly more prevalent and CACS values and HbA1c, NT-proBNP, and GDF-15 levels were significantly higher (all p < 0.001) in the elderly group compared to the middle-aged group. Multivariate ridge regression analysis revealed a significant positive association between GDF-15 and CACS (middle-aged group: β = 0.072, p = 0.333; elderly group: β = 0.148, p = 0.003), and between GDF-15 and ABI (middle-aged group: β = 0.062, p = 0.393; elderly group: β = 0.088, p = 0.041) only in the elderly group. Our results show that GDF-15 is not only a useful biomarker of inflammation but can also predict early signs of asymptomatic atherosclerosis, especially in elderly people with chronic systemic inflammation associated with aging (inflammaging).

New diagnostic strategy for multiple myeloma: A review

Multiple myeloma (MM) is the second most prevalent hematological malignancy and is distinguished by the aberrant proliferation of monoclonal plasma cells inside the bone marrow and production of M-protein. This condition frequently results in bone deterioration, acute kidney damage, anemia, and hypercalcemia. However, the clinical manifestations and accompanying symptoms of MM vary and may change as the condition evolves. Therefore, diagnosis of MM is difficult. At present, the confirmation of MM diagnosis necessitates the use of bone marrow biopsy, a procedure that is both invasive and challenging for assessing dynamic alterations in the disease. The integration of laboratory testing technologies with imaging technology has the potential to enhance the diagnostic effectiveness and provide a thorough evaluation of disease progression and prognosis in patients with MM. All the examination methods have advantages and disadvantages. Therefore, diagnosis is determined by the application of clinical characteristics, serological tests, and imaging investigations.

Overexpression of Growth Differentiation Factor 15 in Glioblastoma Stem Cells Promotes Their Radioresistance

GSCs play an important role in GBM recurrence. Understanding the resistance mechanisms in these cells is therefore crucial for radiation therapy optimization. In this study, using patient-derived GSCs, we demonstrate that GDF15, a cytokine belonging to the TGF-β superfamily, is regulated by irradiation (IR) and the transcription factor WWTR1/TAZ. Blocking WWTR1/TAZ using specific siRNAs significantly reduces GDF15 basal expression and reverses the upregulation of this cytokine induced by IR. Furthermore, we demonstrate that GDF15 plays an important role in GSC radioresistance. Targeting GDF15 expression by siRNA in GSCs expressing high levels of GDF15 sensitizes the cells to IR. In addition, we also found that GDF15 expression is critical for GSC spheroid formation, as GDF15 knockdown significantly reduces the number of GSC neurospheres. This study suggests that GDF15 targeting in combination with radiotherapy may be a feasible approach in patients with GBM.

GDF15 deficiency hinders human trophoblast invasion to mediate pregnancy loss through downregulating Smad1/5 phosphorylation

Growth differentiation factor 15 (GDF15) belongs to the Transforming growth factor β(TGF-β) superfamily. The decrease of GDF15 in the serum of pregnant women was associated with miscarriage. Both IHC and ELISA assays showed that GDF15 in trophoblast tissue and serum of pregnant women who miscarried was significantly lower than in those who had a live birth. GDF15 deficiency was associated with embryo resorption in GDF15 knockout mice through CRIPSR editing. In addition, the migration and invasion ability of HTR-8/SVneo and JEG-3 cells were promoted by GDF15. Mechanistically, GDF15 increased Smad1/5 phosphorylation, resulting in upregulating SNAI1/2, VIMENTIN and downregulating E-CADHERIN. A dual-luciferase reporter assay confirmed that Smad-binding elements (SBE) and/or GC-rich motifs were activated and target genes such as SNAI1/2, SERPINE1, and TIMP3 were transcriptionally regulated by GDF15/Smad5 signaling. Therefore, our data revealed a crucial role of GDF15 on invasion of trophoblast by upregulating the activity of TGF-β/Smad1/5 pathway.

Association of GDF15 levels with body mass index and endocrine status in β-thalassaemia

OBJECTIVE

GDF15 has emerged as a stress-induced hormone, acting on the brain to reduce food intake and body weight while affecting neuroendocrine function. Very high GDF15 levels are found in thalassaemia, where growth, energy balance and neuroendocrine function are impaired. We examined the relationships between GDF15 and anthropometric measures and endocrine status in β-thalassaemia.

DESIGN

Cross sectional study.

PATIENTS

All β-thalassaemia patients attending the thalassaemia unit of Colombo North Teaching Hospital for blood transfusions.

MEASUREMENTS

Anthropometric data, appetite scores, circulating GDF15, IGF, thyroid and reproductive hormone levels in 103 β-thalassaemia patients were obtained.

RESULTS

GDF15 levels were markedly elevated in thalassaemia patients (24.2-fold with β-thalassaemia major compared with healthy controls). Among patients with β-thalassaemia major, the relationship between GDF15 and body mass index (BMI) was curvilinear with all individuals with GDF15 levels above 24,000 pg/mL having a BMI below 20 kg/m2 . After adjustment for BMI, age and Tanner stage, serum IGF1 concentrations correlated negatively with GDF15 in all thalassaemia patients (β = -.027, p = .02). We found a significant positive relationship between GDF15 and gonadotropin (in both sexes) and testosterone (in males).

CONCLUSIONS

GDF15 levels were markedly elevated in patients with β-thalassaemia and its association with BMI is consistent with the known effect of GDF15 to reduce body weight. The inverse association between GDF15 with IGF1 levels may reflect a neuroendocrine impact of GDF15 or an indirect effect via impaired nutritional state. The positive association with testosterone in males and gonadotropins in both sexes, was surprising and should prompt further GDF15 studies on the hypothalamic pituitary gonadal axis.

Growth Differentiation Factor 15 and Clinical Outcomes in Japanese Patients With Heart Failure

BACKGROUND

Heart failure (HF) is an increasing health problem associated with a high mortality rate. Growth differentiation factor (GDF) 15, a stress response cytokine belonging to the transforming growth factor-β superfamily, is associated with poor clinical outcomes in a broad spectrum of cardiovascular diseases. However, the prognostic usefulness of GDF15 in Japanese patients with HF remains unclear.Methods and Results: We measured serum concentrations of GDF15 and B-type natriuretic peptide (BNP) in 1,201 patients with HF. All patients were prospectively followed for a median period of 1,309 days. In all, 319 HF-related events and 187 all-cause deaths occurred during the follow-up period. Kaplan-Meier analysis demonstrated that, among GDF15 tertiles, the highest tertile group had the greatest risk of HF-related events and all-cause mortality. Multivariate Cox proportional hazard regression analysis demonstrated that the serum GDF15 concentration was an independent predictor of HF-related events and all-cause deaths after adjusting for confounding risk factors. Serum GDF15 improved the prediction capacity for all-cause deaths and HF-related events with a significant net reclassification index and integrated discrimination improvement. Subgroup analysis in patients with HF with preserved ejection fraction also showed the prognostic usefulness of GDF15.

CONCLUSIONS

Serum GDF15 concentrations were associated with HF severity and clinical outcomes, indicating that GDF15 could provide additional clinical information to track the health status of patients with HF.

Different Kinetics of Serum ADAMTS13, GDF-15, and Neutrophil Gelatinase-Associated Lipocalin in the Early Phase of Aneurysmal Subarachnoid Hemorrhage

Growth differentiation factor 15 (GDF-15), neutrophil gelatinase-associated lipocalin (NGAL), and ADAMTS13 have previously been implicated in the pathophysiological processes of SAH. In the present study, we aim to examine their role in the early period of SAH and their relationship to primary and secondary outcomes. Serum samples were collected at five time periods after SAH (at 24 h (D1), at 72 h (D3), at 120 h (D5), at 168 h (D7) and at 216 h (D9), post-admission) and) were measured by using MILLIPLEX Map Human Cardiovascular Disease (CVD) Magnetic Bead Panel 2. We included 150 patients with SAH and 30 healthy controls. GDF-15 levels at D1 to D9 were significantly associated with a 3-month unfavorable outcome. Based on the ROC analysis, in patients with a good clinical grade at admission (WFNS I-III), the GDF-15 value measured at time point D3 predicted a 3-month unfavorable outcome (cut-off value: 3.97 ng/mL, AUC:0.833, 95%CI: 0.728-0.938, sensitivity:73.7%, specificity:82.6%, p < 0.001). Univariate binary logistic regression analysis showed that serum NGAL levels at D1-D5 and ADAMTS13 levels at D7-D9 were associated with MVS following SAH. GDF-15 is an early indicator of a poor 3-month functional outcome even in patients with mild clinical conditions at admission.

Growth Differentiation Factor-15 and Clinical Outcomes in Japanese Patients With Ischemic Heart Disease

Background

Despite a reduction in the rate of thrombotic events, ischemic heart disease (IHD) remains a key medical problem associated with high major bleeding and mortality in Asian patients with IHD. Growth differentiation factor (GDF)-15, a stress-response cytokine belonging to the transforming growth factor beta superfamily, is reportedly associated with poor clinical outcomes in Western patients with IHD. However, the clinical significance of GDF-15 in Asian patients with IHD has not yet been fully elucidated.

Objectives

The aim of the present study was to examine the impact of serum GDF-15 on clinical outcomes in Japanese patients with IHD.

Methods

Serum GDF-15 levels were evaluated in 632 consecutive patients with IHD. All patients were followed up for a median period of 2.8 years. The primary endpoint was the all-cause mortality rate. Secondary endpoints were major adverse cardiovascular events (MACE), heart failure (HF)-related rehospitalization, bleeding, and thrombotic events.

Results

Serum GDF-15 levels were elevated in acute coronary syndrome, severe coronary artery disease, and the major Japanese version of the high bleeding risk criteria. Multivariate Cox proportional hazards regression analysis demonstrated that GDF-15 was an independent predictor of all-cause mortality, MACE, HF-related rehospitalizations, and bleeding events after adjusting for confounding risk factors but not for thrombotic events. Adding GDF-15 to risk factors significantly improved the net reclassification index and integrated discrimination improvement for all-cause deaths, MACE, HF-related rehospitalization, and bleeding events.

Conclusions

Serum GDF-15 could be a feasible marker for major bleeding and adverse clinical outcomes in Japanese patients with IHD.

Cardiac markers and cardiovascular disease in chronic kidney disease

Cardiovascular disease (CVD) is prevalent in patients with chronic kidney disease (CKD) and it is responsible for approximately half of all CKD-related deaths. CVDs are the primary cause of death in hemodialysis patients due to major adverse cardiovascular events. Therefore, better approaches for differentiating chronic hemodialysis patients at higher cardiovascular risk will help physicians improve clinical outcomes. Hence, there is an urgent need to discover feasible and reliable cardiac biomarkers to improve diagnostic accuracy, reflect myocardial injury, and identify high-risk patients. Numerous biomarkers that have significant prognostic value with respect to adverse CVD outcomes in the setting of mild to severe CKD have been identified. Therefore, a better understanding of the positive clinical impact of cardiac biomarkers on CVD patient outcomes is an important step toward prevention and improving treatment in the future. In this review, we address the relationship between cardiovascular biomarkers and CKD treatment strategies to elucidate the underlying importance of these biomarkers to patient outcomes.

Altered circulating GDF-15 level predicts sex hormone imbalance in males with major depressive disorder

BACKGROUND

It has been hypothesized that higher growth differentiation factor 15 (GDF15) level and lower testosterone/ estradiol (T/E) ratio are associated with major depressive disorder (MDD), yet the underlying effect of serum GDF15 on hinting the T/E ratio imbalance is not fully understood. We observed the correlation between serum T/E ratio and circulating GDF15 in male depressed cohort.

METHODS

The sample consisted of participants (aged 18 ~ 65 years) from the Renmin Hospital of Wuhan University with MDD (n = 412) defined according to a Structured Clinical Interview for DSM-V (SCID), and male healthy controls (n = 137). Serum levels of testosterone, estradiol, and depression risk biomarkers (thyroid hormone, lipids, hs-CRP, Tenascin-C [TNC], GDF15, KLF4, Gas6, and sgp130) were measured. The associations among log-transformed T/E ratio and these biomarkers were analyzed using univariate correlation analysis, category analyses, and linear regression adjusting for standard risk factors.

RESULTS

Of the sample, 36.89% had lower T/E ratio (< 10:1) and 10.20% had higher T/E ratio (> 20:1). After multivariable adjustment, T/E ratio was negatively associated with GDF15 (-0.095 [95% CI -0.170 ~ -0.023] standard deviation [SD] change per SD increase in lg[T/E], P = 0.015) and inversely related to TNC (-0.085 [95% CI -0.167 ~ 0.003] standard deviation [SD] change per SD increase in lg[T/E], P = 0.048). Serum T/E ratio was negatively associated with GDF15 level in both FT3, TSH and HDL strata, whereas this association was not observed in TNC. In T/E ratio strata analyses, there is a significant and negative correlation among T/E ratio and GDF15 in depressive patients with sex hormone imbalance, yet this relationship was not investigated in patients with sex hormone balance.

CONCLUSION

In our community-based observation, circulating GDF-15 level was greatly and inversely associated with serum T/E ratio, indicating that higher GDF-15 alerts sex hormone imbalance in patients with MDD.

GDF-15 Is Associated with Poor Physical Function in Prefrail Older Adults with Diabetes

Introduction

Growth differentiation factor 15 (GDF-15) has been shown to be a metabolic and appetite regulator in diabetes mellitus (DM) and obesity. We aimed to investigate (i) the association between GDF-15 and DM with and without poor physical function independent of inflammation and (ii) the prediction model for poor physical function in prefrail older adults.

Methods

A cross-sectional study of 108-prefrail participants ≥60 years recruited for multidomain interventions. Data was collected for demographics, cognition, function, frailty, nutrition, handgrip strength (HGS), short physical performance battery (SPPB), and gait speed. Serum concentrations of GDF-15, IL-6, and TNF-α were measured. GDF-15 was classified into tertiles (T1, T2, and T3), and its association was studied with DM and physical function (DM poor physical function, DM no poor physical function, no DM poor physical function, and no DM no poor physical function).

Results

Compared with T1, participants in T3 were significantly older, had a lower education level, had almost three times higher prevalence of DM, slower gait speed, longer chair-stand time, and lower SPPB scores. On multivariate analysis, the odds of having both DM and poor physical performance compared to having no DM and no poor physical performance were significantly higher in GDF-15 T3 vs. GDF-15 T1 (aOR 9.7, 95% CI 1.4-67.7; p = 0.021), and the odds of having DM no poor physical function compared to having no DM and no poor physical performance were significantly higher in GDF-15 T2 (aOR 12.7, 95% CI 1.1-143.7; p = 0.040) independent of BMI, IL-6, TNF-α, nutrition, physical function, education, age, and gender.

Conclusion

The association of GDF-15 with DM-associated poor physical function is independent of inflammation in prefrail older adults. Its causal-association link needs to be determined in longitudinal studies.

Metformin and growth differentiation factor 15 (GDF15) in type 2 diabetes mellitus: A hidden treasure

Type 2 diabetes mellitus (T2DM) is a chronic endocrine disorder due to the reduction of insulin sensitivity and relative deficiency of insulin secretion. Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor beta (TGF-β) superfamily and was initially identified as macrophage inhibitory cytokine-1 (MIC-1). GDF15 is considered a cytokine with an anti-inflammatory effect and increases insulin sensitivity, reduces body weight, and improves clinical outcomes in diabetic patients. GDF15 acts through stimulation of glial-derived neurotrophic factor (GDNF) family receptor α-like (GFRAL), which is highly expressed in the brain stem to induce taste aversion. Metformin belongs to the group of biguanides that are derived from the plant Galega officinalis. It is interesting to note that metformin is an insulin-sensitizing agent used as a first-line therapy for T2DM that has been shown to increase the circulating level of GDF15. Thus, the present review aims to determine the critical association of the GDF15 biomarker in T2DM and how metformin agents affect it. This review illustrates that metformin activates GDF15 expression, which reduces appetite and leads to weight loss in both diabetic and nondiabetic patients. However, the present review cannot give a conclusion in this regard. Therefore, experimental, preclinical, and clinical studies are warranted to confirm the potential role of GDF15 in T2DM patients.

Frailty biomarkers under the perspective of geroscience: A narrative review

Cellular and molecular aging biomarkers might contribute to identify at-risk individuals for frailty before overt clinical manifestations appear. Although studies on the associations of aging biomarkers and frailty exist, no investigation has gathered this information using a structured framework for identifying aging biomarkers; as a result, the evidence on frailty and aging biomarkers is diffuse and incomplete. Therefore, this narrative review aimed to gather information on the associations of the hallmarks of aging and frailty under the perspective of geroscience. The literature on human studies on this topic is sparse and mainly composed of cross-sectional investigations performed in small study samples. The main putative aging biomarkers associated to frailty were: mitochondrial DNA copy number (genomic instability and mitochondrial dysfunction), telomere length (telomere attrition), global DNA methylation (epigenetic alterations), Hsp70 and Hsp72 (loss of proteostasis), IGF-1 and SIRT1 (deregulated nutrient-sensing), GDF-15 (mitochondrial dysfunction, cellular senescence and altered intercellular communication), CD4 + and CD8 + cell percentages (cellular senescence), circulating osteogenic progenitor (COP) cells (stem cell exhaustion), and IL-6, CRP and TNF-alpha (altered intercellular communication). IGF-1, SIRT1, GDF-15, IL-6, CRP and TNF-alpha presented more evidence among these biomarkers, highlighting the importance of inflammation and nutrient sensing on frailty. Further longitudinal studies investigating biomarkers across the hallmarks of aging would provide valuable information on this topic.

Chemokines network in bone metastasis: Vital regulators of seeding and soiling

Chemokines are well equipped with chemo-attractive signals that can regulate cancer cell trafficking to specific organ sites. Currently, updated concepts have revealed the diverse role of chemokines in the biology of cancer initiation and progression. Genomic instabilities and alterations drive tumor heterogeneity, providing more options for the selection and metastatic progression to cancer cells. Tumor heterogeneity and acquired drug resistance are the main obstacles in managing cancer therapy and the primary root cause of metastasis. Studies emphasize that multiple chemokine/receptor axis are involved in cancer cell-mediated organ-specific distant metastasis. One of the persuasive mechanisms for heterogeneity and subsequent events is sturdily interlinked with the crosstalk between chemokines and their receptors on cancer cells and tissue-specific microenvironment. Among different metastatic niches, skeletal metastasis is frequently observed in the late stages of prostate, breast, and lung cancer and significantly reduces the survival of cancer patients. Therefore, it is crucial to elucidate the role of chemokines and their receptors in metastasis and bone remodeling. Here, we review the potential chemokine/receptor axis in tumorigenesis, tumor heterogeneity, metastasis, and vicious cycle in bone microenvironment.

The Common H202D Variant in GDF-15 Does Not Affect Its Bioactivity but Can Significantly Interfere with Measurement of Its Circulating Levels

BACKGROUND

There is growing interest in the measurement of growth differentiation factor 15 (GDF-15) in a range of disorders associated with cachexia. We undertook studies to determine whether a common histidine (H) to aspartate (D) variant at position 202 in the pro-peptide (position 6 in the mature peptide) interfered with its detection by 3 of the most commonly used immunoassays.

METHODS

Three synthetic GDF-15-forms (HH homo-, HD hetero-, and DD-homodimers) were measured after serial dilution using Roche Elecsys®, R&D QuantikineTM ELISA, and MSD R&D DuoSet® immunoassays. GDF-15 concentrations were measured by the Roche and the MSD R&D immunoassays in 173 genotyped participants (61 HH homozygotes, 59 HD heterozygotes, and 53 DD homozygotes). For the comparative statistical analyses of the GDF-15 concentrations, we used non-parametric tests, in particular Bland-Altman difference (bias) plots and Passing-Bablok regression. The bioactivity of the 2 different homodimers was compared in a cell-based assay in HEK293S-SRF-RET/GFRAL cells.

RESULTS

The Roche assay detected H- and D-containing peptides similarly but the R&D reagents (Quantikine and DuoSet) consistently underreported GDF-15 concentrations in the presence of the D variant. DD dimers had recoveries of approximately 45% while HD dimers recoveries were 62% to 78%. In human serum samples, the GDF-15 concentrations reported by the R&D assay were a median of 4% lower for HH, a median of 36% lower for HD, and a median of 61% lower for DD compared to the Roche assay. The bioactivities of the HH and DD peptides were indistinguishable.

CONCLUSIONS

The D variant of GDF-15 substantially affects its measurement by a commonly used immunoassay, a finding that has clear implications for its interpretation in research and clinical settings.

The Potential Role of Growth Differentiation Factor 15 in COVID-19: A Corollary Subjective Effect or Not?

Coronavirus disease 2019 (COVID-19) is primarily caused by various forms of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) variants. COVID-19 is characterized by hyperinflammation, oxidative stress, multi-organ injury (MOI)-like acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). Different biomarkers are used in the assessment of COVID-19 severity including D-dimer, ferritin, lactate dehydrogenase (LDH), and hypoxia-inducible factor (HIF). Interestingly, growth differentiation factor 15 (GDF15) has recently become a potential biomarker correlated with the COVID-19 severity. Thus, this critical review aimed to determine the critical association between GDF15 and COVID-19. The perfect function of GDF15 remains not well-recognized; nevertheless, it plays a vital role in controlling cell growth, apoptosis and inflammatory activation. Furthermore, GDF15 may act as anti-inflammatory and pro-inflammatory signaling in diverse cardiovascular complications. Furthermore, the release of GDF15 is activated by various growth factors and cytokines including macrophage colony-stimulating factor (M-CSF), angiotensin II (AngII) and p53. Therefore, higher expression of GDF15 in COVID-19 might a compensatory mechanism to stabilize and counteract dysregulated inflammatory reactions. In conclusion, GDF15 is an anti-inflammatory cytokine that could be associated with the COVID-19 severity. Increased GDF15 could be a compensatory mechanism against hyperinflammation and exaggerated immune response in the COVID-19. Experimental, preclinical and large-scale clinical studies are warranted in this regard.

The Upregulation of Caffeic Acid Phenethyl Ester on Growth Differentiation Factor 15 Inhibits Transforming Growth Factor β/Smad Signaling in Bladder Carcinoma Cells

Growth differentiation factor 15 (GDF15) is known as a TGFβ-like cytokine acting on the TGFβ receptor to modulate target genes. GDF15 is regarded as a tumor suppressor gene in the human bladder and the caffeic acid phenethyl ester (CAPE) induces GDF15 expression to inhibit the tumor growth in vitro and in vivo. However, the interactions among GDF15, CAPE, and TGFβ/Smads signaling in the human bladder carcinoma cells remain unexplored. Results revealed that TGFβ downregulated the expression of GDF15 via the activation of Smad 2/3 and Smad 1/5. Induction of GDF15 on its downstream genes, NDRG1 and maspin, is dependent on the TGFβ/Smad pathways. Moreover, TGFβ blocked the CAPE-inducing expressions of GDF15, maspin, and NDRG1. Pretreatment of TGF receptor kinase inhibitor not only blocked the activation of TGFβ but also attenuated the activation of GDF15 on the expressions of maspin and NDRG1. The CAPE treatment attenuated the activation of TGFβ on cell proliferation and invasion. Our findings indicate that TGFβ downregulated the expressions of GDF15, maspin, and NDRG1 via TGFβ/Smad signaling. Whereas, CAPE acts as an antagonist on TGFβ/Smad signaling to block the effect of TGFβ on the GDF15 expression and cell proliferation and invasion in bladder carcinoma cells.

Macrophage inhibitory cytokine-1 in cancer: Beyond the cellular phenotype

Despite technological advances in diagnostic abilities and improved treatment methods, the burden of cancers remains high, leading to significant morbidity and mortality. One primary reason is that cancer cell secretory factors modulate the tumor microenvironment, supporting tumor growth and circumvents anticancer activities of conventional therapies. Macrophage inhibitory cytokine-1 (MIC-1) is a pleiotropic cytokine elevated in various cancers. MIC-1 regulates various cancer hallmarks, including sustained proliferation, tumor-promoting inflammation, avoiding immune destruction, inducing invasion, metastasis, angiogenesis, and resisting cell death. Despite these facts, the molecular regulation and downstream signaling of MIC-1 in cancer remain elusive, partly because its receptor (GFRAL) was unknown until recently. Binding of MIC-1 to GFRAL recruits the coreceptor tyrosine kinase RET to execute its downstream signaling. So far, studies have shown that GFRAL expression is restricted to the brain stem and is responsible for MIC-1/GFRAL/RET-mediated metabolic disorders. Nevertheless, abundant levels of MIC-1 expression have been reported in all cancer types and have been proposed as a surrogate biomarker. Given the ubiquitous expression of MIC-1 in cancers, it is crucial to understand both upstream regulation and downstream MIC-1/GFRAL/RET signaling in cancer hallmark traits.

GDF15 Is an Eribulin Response Biomarker also Required for Survival of DTP Breast Cancer Cells

Simple Summary

Drug tolerant persister (DTP) cells are a unique, small sub-population of cancer cells that maintain viability under anti-cancer cytotoxic treatments. These cells enter into a reversible drug-tolerant state, which is believed to be the root of tumor recurrence. Therefore, there is a great need to find novel ways to monitor and eliminate DTP cells. We have identified the secretion of GDF15 as a response biomarker of eribulin treatment, as well as a specific biomarker of DTP cells in breast cancer. GDF15 expression is low or absent in cells sensitive to eribulin, strongly upregulated during response to the drug, and then downregulated when stable resistance is ultimately established. We have also shown that GDF15 plays a direct role in the survival of DTP cells. Thus, targeting GDF15 could help eradicate DTP cells and block the onset of stable acquired resistance. Most importantly, our data suggest that the combination of eribulin plus a GDF15 neutralizing antibody might be beneficial in the treatment of breast cancer.

Abstract

Drug tolerant persister (DTP) cells enter into a reversible slow-cycling state after drug treatment. We performed proteomic characterization of the breast cancer (BC) DTP cell secretome after eribulin treatment. We showed that the growth differentiation factor 15 (GDF15) is a protein significantly over-secreted upon eribulin treatment. The biomarker potential of GDF15 was confirmed in 3D-cell culture models using BC cells lines and PDXs, as well as in a TNBC in vivo model. We also found that GDF15 is required for survival of DTP cells. Direct participation of GDF15 and its receptor GFRAL in eribulin-induction of DTPs was established by the enhanced cell killing of DTPs by eribulin seen under GDF15 and GFRAL loss of function assays. Finally, we showed that combination therapy of eribulin plus an anti-GDF15 antibody kills BC-DTP cells. Our results suggest that targeting GDF15 may help eradicate DTP cells and block the onset of acquired resistance.

Deletion of Gdf15 Reduces ER Stress-induced Beta-cell Apoptosis and Diabetes

Endoplasmic reticulum (ER) stress contributes to pancreatic beta-cell apoptosis in diabetes, but the factors involved are still not fully elucidated. Growth differentiation factor 15 (GDF15) is a stress response gene and has been reported to be increased and play an important role in various diseases. However, the role of GDF15 in beta cells in the context of ER stress and diabetes is still unclear. In this study, we have discovered that GDF15 promotes ER stress-induced beta-cell apoptosis and that downregulation of GDF15 has beneficial effects on beta-cell survival in diabetes. Specifically, we found that GDF15 is induced by ER stress in beta cells and human islets, and that the transcription factor C/EBPβ is involved in this process. Interestingly, ER stress-induced apoptosis was significantly reduced in INS-1 cells with Gdf15 knockdown and in isolated Gdf15 knockout mouse islets. In vivo, we found that Gdf15 deletion attenuates streptozotocin-induced diabetes by preserving beta cells and insulin levels. Moreover, deletion of Gdf15 significantly delayed diabetes development in spontaneous ER stress-prone Akita mice. Thus, our findings suggest that GDF15 contributes to ER stress-induced beta-cell apoptosis and that inhibition of GDF15 may represent a novel strategy to promote beta-cell survival and treat diabetes.

Investigating the combination of plasma amyloid-beta and geroscience biomarkers on the incidence of clinically meaningful cognitive decline in older adults

We investigated combining a core AD neuropathology measure (plasma amyloid-beta [Aβ] _42/40) with five plasma markers of inflammation, cellular stress, and neurodegeneration to predict cognitive decline. Among 401 participants free of dementia (median [IQR] age, 76 [73-80] years) from the Multidomain Alzheimer Preventive Trial (MAPT), 28 (7.0%) participants developed dementia, and 137 (34.2%) had worsening of clinical dementia rating (CDR) scale over 4 years. In the models utilizing plasma Aβ alone, a tenfold increased risk of incident dementia (nonsignificant) and a fivefold increased risk of worsening CDR were observed as each nature log unit increased in plasma Aβ levels. Models incorporating Aβ plus multiple plasma biomarkers performed similarly to models included Aβ alone in predicting dementia and CDR progression. However, improving Aβ model performance for composite cognitive score (CCS) decline, a proxy of dementia, was observed after including plasma monocyte chemoattractant protein 1 (MCP1) and growth differentiation factor 15 (GDF15) as covariates. Participants with abnormal Aβ, GDF15, and MCP1 presented higher CCS decline (worsening cognitive function) compared to their normal-biomarker counterparts (adjusted β [95% CI], - 0.21 [- 0.35 to - 0.06], p = 0.005). In conclusion, our study found limited added values of multi-biomarkers beyond the basic Aβ models for predicting clinically meaningful cognitive decline among non-demented older adults. However, a combined assessment of inflammatory and cellular stress status with Aβ pathology through measuring plasma biomarkers may improve the evaluation of cognitive performance.

Plasma growth differentiation factor-15 in patients with "lone" atrial fibrillation

Background

Growth differentiation factor‐15 (GDF‐15) is a member of the transforming growth factor β superfamily, correlated with various stimuli, including cardiovascular disease. The association between plasma GDF‐15 level and “lone” AF, that is, AF of unknown etiology (UeAF), is uncertain.

Methods

All patients aged 60 years or younger. AF patients were hospitalized for primary catheter ablation. Patients with sinus rhythm admitted for other diseases during the same period were included in the control group. ELISA was used to measure plasma GDF‐15 concentrations.

Results

60 UeAF patients, 60 paroxysmal AF (PAF) patients, and 70 control patients were enrolled. The mean age was 44.6 years. In the UeAF group, no patients had traditional clinical risk factors. The plasma GDF‐15 level in the UeAF group was (1028.5 ± 180.5) pg/ml, higher than in the control group, and moderately lower than in the PAF group. In all patients, positive correlations were found between plasma GDF‐15 level and age (R = 0.210, p < 0.05), and between plasma GDF‐15 level and left atrial diameter (LAD; R = 0.338, p < 0.05; in the UeAF group: R = 0.475, p < 0.05; in the PAF group: R = 0.504, p < 0.05).

Conclusions

Our study first investigated the role of GDF‐15 in UeAF. The plasma GDF‐15 level in UeAF patients was higher than in sinus rhythm patients and lower than in PAF patients. Moreover, GDF‐15 was positively correlated with age and LAD. The role of GDF‐15 in UeAF needs further study.

Serum GDF-15 Predicts In-Hospital Mortality and Arrhythmic Risks in Patients With Acute Myocardial Infarction

This study aims to evaluate the association of serum growth differentiation factor 15 (GDF-15) with in-hospital mortality and arrhythmic risks in patients with acute myocardial infarction (AMI). A total of 296 consecutive patients with AMI were enrolled in our hospital from Jan. 2018 to Dec. 2020. Serum GDF-15 levels were measured at baseline. The primary endpoint was in-hospital all-cause mortality, and the secondary endpoint was major adverse cardiac events (MACEs) during hospitalization, defined as a composite of cardiovascular death, heart failure, sustained ventricular arrhythmias (ventricular tachycardia or ventricular fibrillation), and bleeding. During hospitalization, patients with a higher GDF-15 level had significantly higher incidences of in-hospital mortality (7.4% vs 1.4%; P = .02) and MACEs (9.5% vs 20.9%, P < .01) than those with a lower GDF-15 level. Multivariate logistic regression analysis showed that a higher GDF-15 level was significantly associated with increased risks of in-hospital mortality (OR = 1.92, 95% CI: 1.44-2.50; P < .01) and MACEs (OR = 2.19, 95% CI: 1.56-2.77; P < .01). In conclusion, GDF-15 was associated with the risks of in-hospital mortality and MACEs, indicating that it should be a prognostic biomarker for patients with AMI.

FGF21 outperforms GDF15 as a diagnostic biomarker of mitochondrial disease in children

Several studies have shown serum fibroblast growth factor 21 (FGF21) and growth differentiation factor 15 (GDF15) levels are elevated in patients with mitochondrial disease (MD) where myopathy is a feature. In this study we investigated the utility of FGF21 and GDF15 as biomarkers for MD in a phenotypically and genotypically diverse pediatric cohort with suspected MD against a panel of healthy controls and non-mitochondrial disease controls with some overlapping clinical features. Serum was collected from 56 children with MD, 104 children with non-mitochondrial disease (27 neuromuscular, 26 cardiac, 21 hepatic, 30 renal) and 30 pediatric controls. Serum FGF21 and GDF15 concentrations were measured using ELISA, and their ability to detect MD was determined. Median FGF21 and GDF15 serum concentrations were elevated 17-fold and 3-fold respectively in pediatric MD patients compared to the healthy control group. Non-mitochondrial disease controls had elevated serum GDF15 concentrations while FGF21 concentrations were in the normal range. Elevation of GDF15 in a range of non-mitochondrial pediatric disorders limits its use as a MD biomarker. FGF21 was elevated in MD patients with a spectrum of clinical phenotypes, including those without myopathy. Serum FGF21 had an area under the receiver operating characteristic curve of 0.87, indicating good ability to discriminate between pediatric MD and healthy and non-mitochondrial disease controls. Triaging of pediatric MD patients by clinical phenotyping and serum FGF21 testing, followed by massively parallel sequencing, may enable more rapid diagnosis of pediatric MD.

GDF-15, a future therapeutic target of glucolipid metabolic disorders and cardiovascular disease

Growth and differentiation factor 15 (GDF-15) was discovered as a member of the transforming growth factor β (TGF-β) superfamily and the serum level of GDF-15 was significantly correlated with glucolipid metabolic disorders (GLMD) and cardiovascular diseases. In 2017, a novel identified receptor of GDF-15-glial-derived neurotrophic factor receptor alpha-like (GFRAL) was found to regulate energy homeostasis (such as obesity, diabetes and non-alcoholic fatty liver disease (NAFLD)). The function of GDF-15/GFRAL in suppressing appetite, enhancing glucose/lipid metabolism and vascular remodeling has been gradually revealed. These effects make it a potential therapeutic target for GLMD and vascular diseases. In this narrative review, we included and reviewed 121 articles by screening 524 articles from literature database. We primarily focused on the function of GDF-15 and its role in GLMD/cardiovascular diseases and discuss its potential clinical application.

Characterization of atherosclerotic plaques in blood vessels with low oxygenated blood and blood pressure (Pulmonary trunk): role of growth differentiation factor-15 (GDF-15)

BACKGROUND

Growth differentiation factor (GDF)-15 is linked to inflammation, cancer, and atherosclerosis. GDF-15 is expressed in most tissues but is extremely induced under pathological conditions. Elevated serum levels are suggested as a risk factor and a marker for cardiovascular diseases. However, the cellular sources and the effects of GDF-15 on the cardiovascular system have not been completely elucidated including progression, and morphology of atherosclerotic plaques. Thus, this work aimed to characterize the influence of GDF-15 deficiency on the morphology of atherosclerotic plaques in blood vessels with low-oxygen blood and low blood pressure as the pulmonary trunk (PT), in hypercholesterolemic ApoE-/- mice.

METHODS

GDF-15-/- ApoE-/- mice were generated by crossbreeding of ApoE-/-- and GDF-15-/- mice. After feeding a cholesterol-enriched diet (CED) for 20 weeks, samples of the brachiocephalic trunk (BT) and PT were dissected and lumen stenosis (LS) was measured. Furthermore, changes in the cellularity of the PT, amounts of apoptosis-, autophagy-, inflammation- and proliferation-relevant proteins were immunohisto-morphometrically analyzed. Additionally, we examined an atherosclerotic plaque in a human post mortem sample of the pulmonary artery.

RESULTS

After CED the body weight of GDF-15-/-ApoE-/- was 22.9% higher than ApoE-/-. Double knockout mice showed also an 35.3% increase of plasma triglyceride levels, whereas plasma cholesterol was similar in both genotypes. LS in the BT and PT of GDF-15-/-ApoE-/- mice was significantly reduced by 19.0% and by 6.7% compared to ApoE-/-. Comparing LS in PT and BT of the same genotype revealed a significant 38.8% (ApoE-/-) or 26.4% (GDF-15-/-ApoE-/-) lower LS in the PT. Immunohistomorphometry of atherosclerotic lesions in PT of GDF-15-/-ApoE-/- revealed significantly increased levels (39.8% and 7.3%) of CD68 + macrophages (MΦ) and α-actin + smooth muscle cells than in ApoE-/-. The density of TUNEL + , apoptotic cells was significantly (32.9%) higher in plaques of PT of GDF-15-/-ApoE-/- than in ApoE-/-. Analysis of atherosclerotic lesion of a human pulmonary artery showed sm-α-actin, CD68+, TUNEL+, Ki67+, and APG5L/ATG+ cells as observed in PT. COX-2+ and IL-6+ immunoreactivities were predominantly located in endothelial cells and subendothelial space. In BT and PT of GDF15-/-ApoE-/- mice the necrotic area was 10% and 6.5% lower than in ApoE-/-. In BT and PT of GDF15-/-ApoE-/- we found 40% and 57% less unstable plaques than ApoE-/- mice.

CONCLUSIONS

Atherosclerotic lesions occur in both, BT and PT, however, the size is smaller in PT, possibly due to the effect of the low-oxygen blood and/or lower blood pressure. GDF-15 is involved in atherosclerotic processes in BT and PT, although different mechanisms (e.g. apoptosis) in these two vessels seem to exist.

Changes in systemic GDF15 across the adult lifespan and their impact on maximal muscle power: the Copenhagen Sarcopenia Study

BACKGROUND

Although growth differentiation factor 15 (GDF15) is known to increase with disease and is associated with low physical performance, the role of GDF15 in normal ageing is still not fully understood. Specifically, the influence of circulating GDF15 on impairments in maximal muscle power (a major contributor to functional limitations) and the underlying components has not been investigated.

METHODS

Data from 1305 healthy women and men aged 20 to 93 years from The Copenhagen Sarcopenia Study were analysed. Circulating levels of GDF15 and markers of inflammation (tumor necrosis factor-alpha, interleukin-6, and high-sensitivity C-reactive protein) were measured by ELISA (R&D Systems) and multiplex bead-based immunoassays (Bio-Rad). Relative (normalized to body mass), allometric (normalized to height squared), and specific (normalized to leg muscle mass) muscle power were assessed by the Nottingham power rig [leg extension power (LEP)] and the 30 s sit-to-stand (STS) muscle power test. Total body fat, visceral fat, and leg lean mass were assessed by dual energy X-ray absorptiometry. Leg skeletal muscle index was measured as leg lean mass normalized to body height squared.

RESULTS

Systemic levels of GDF15 increased progressively as a function of age in women (1.1 ± 0.4 pg·mL^-1 ·year^-1 ) and men (3.3 ± 0.6 pg·mL^-1 ·year^-1 ) (both P < 0.05). Notably, GDF15 increased at a faster rate from the age of 65 years in women (11.5 ± 1.2 pg·mL^-1 ·year^-1 , P < 0.05) and 70 years in men (19.3 ± 2.3 pg·mL^-1 ·year^-1 , P < 0.05), resulting in higher GDF15 levels in men compared with women above the age of 65 years (P < 0.05). Independently of age and circulatory markers of inflammation, GDF15 was negatively correlated to relative STS power (P < 0.05) but not LEP, in both women and men. These findings were mainly explained by negative associations of GDF15 with specific STS power in women and men (both P < 0.05).

CONCLUSIONS

A J-shaped relationship between age and systemic GDF15 was observed, with men at older age showing steeper increases and elevated GDF15 levels compared with women. Importantly, circulating GDF15 was independently and negatively associated with relative STS power, supporting the potential role of GDF15 as a sensitive biomarker of frailty in older people.

Increased Plasma GDF15 Is Associated with Altered Levels of Soluble VEGF Receptors 1 and 2 in Symptomatic Multiple Myeloma

INTRODUCTION

In multiple myeloma, there is an increase in bone marrow microvascular density and enhanced renal lymphangiogenesis. Increased levels of the proangiogenic protein growth differentiation factor-15 (GDF15) have previously been reported to be associated with poor prognosis in myeloma. A possible association between GDF15 and the soluble forms of vascular endothelial growth factor receptors (sVEGFR) 1 and 2 has not yet been investigated, and a role for these receptors in pathological angiogenesis in myeloma is still to be defined.

METHODS

Plasma levels of GDF15 and sVEGFR1 and 2 were determined by ELISA in patients with smouldering multiple myeloma (sMM), patients with symptomatic multiple myeloma (abbreviated as MM), and healthy controls. The levels were compared between the three groups, and correlation coefficients were calculated, as were Kaplan-Meier curves for GDF15 and sVEGFR1 and sVEGFR2.

RESULTS

Levels of GDF15 were significantly higher in MM than in both patients with sMM and controls. A gradual decrease in mean sVEGFR1 concentration was observed, with MM > sMM > controls. Mean sVEGFR2 was lower in patients with MM than in controls. There was a positive correlation between GDF15 and sVEGFR1, and GDF15 correlated negatively with sVEGFR2. High GDF15 (>3 ng/mL) was associated with poor prognosis.

CONCLUSION

In multiple myeloma, increased expression of GDF15 correlates positively with sVEGFR1 and negatively with sVEGFR2. It is possible that the altered levels of sVEGFR1 and 2 contribute to the increased angio- and lymphangiogenesis observed in myeloma.

Pathophysiological role of growth differentiation factor 15 (GDF15) in obesity, cancer, and cachexia

Growth differentiation factor 15 or macrophage inhibitory cytokine-1 (GDF15/MIC-1) is a divergent member of the transforming growth factor β superfamily and has a diverse pathophysiological roles in cancers, cardiometabolic disorders, and other diseases. GDF15 controls hematopoietic growth, energy homeostasis, adipose tissue metabolism, body growth, bone remodeling, and response to stress signals. The role of GDF15 in cancer development and progression is complicated and depends on the specific cancer type, stage, and tumor microenvironment. Recently, research on GDF15 and GDF15-associated signaling has accelerated due to the identification of the GDF15 receptor: glial cell line-derived neurotrophic factor (GDNF) family receptor α-like (GFRAL). Therapeutic interventions to target GDF15 and/or GFRAL revealed the mechanisms that drive its activity and might improve overall outcomes of patients with metabolic disorders and cancer. This review highlights the structure and functions of GDF15 and its receptor, emphasizing the pleiotropic role of GDF15 in obesity, tumorigenesis, metastasis, immunomodulation, and cachexia.

Caffeic acid phenethyl ester inhibits the growth of bladder carcinoma cells by upregulating growth differentiation factor 15

BACKGROUND

Caffeic acid phenethyl ester (CAPE), a bioactive component of propolis, has beneficial effects on cancer prevention. Growth differentiation factor 15 (GDF15) is an antitumor gene of bladder cancer. Therefore, this study investigated the anti-cancer effect of CAPE on bladder carcinoma cells and related mechanisms.

METHODS

The expressions of GDF15, N-myc downstream-regulated gene 1 (NDRG1), and maspin, and the activations of ERK, JNK, p38, and AMPKα1/2 in human bladder cells after gene transfection or knockdown were determined by immunoblot, RT-qPCR, and reporter assays. The assays of 5-ethynyl-2'-deoxyuridine (EdU), CyQUANT cell proliferation, and Matrigel invasion, and the xenograft animal study were used to assess the cell proliferation, invasion, and tumorigenesis.

RESULTS

GDF15 expression in epithelial cells was negatively correlated with neoplasia in vitro. Also, GDF15 exhibits in bladder fibroblasts and smooth muscle cells. CAPE-induced expressions of NDRG1 and maspin decreased cell proliferation and invasion of bladder carcinoma cells in a GDF15-dependent manner in vitro. The xenograft animal study suggesting CAPE attenuated tumor growth in vivo. CAPE increased phosphorylation of ERK, JNK, p38, and AMPKα1/2 to modulate the GDF15 expressions. Pretreatments with ERK, JNK, or p38 inhibitors partially inhibited the CAPE effects on the inductions of GDF15, NDRG1, or maspin. Knockdown of AMPKα1/2 attenuated the CAPE-induced GDF15 expression and cell proliferation in bladder carcinoma cells.

CONCLUSIONS

Our findings indicate that CAPE is a promising agent for anti-tumor growth in human bladder carcinoma cells via the upregulation of GDF15.

Negative Regulators of Inflammation Response to the Dynamic Expression of Cytokines in DF-1 and MDCK Cells Infected by Avian Influenza Viruses

The H5N1 and H9N2 avian influenza viruses (AIVs) seriously endanger the poultry industry and threaten human health. Characteristic inflammatory responses caused by H5N1 and H9N2 AIVs in birds and mammals result in unique clinical manifestations. The role of anti-inflammatory regulators, PTX3, Del-1, and GDF-15, in H5N1 and H9N2-AIV-mediated inflammation in birds and mammals has not yet been verified. Here, the expression of PTX3, Del-1, and GDF-15 in DF-1 and MDCK cells infected with H5N1 and H9N2 AIVs and their effect on inflammatory cytokines were analyzed. Infection with both AIVs increased PTX3, Del-1, and GDF-15 expression in DF-1 and MDCK cells. Infection with H9N2 or H5N1 AIV in DF-1 and MDCK cells with overexpression of all three factors, either alone or in combination, inhibited the expression of tested inflammatory cytokines. Furthermore, co-expression of PTX3, Del-1, and GDF-15 enhanced the inhibition, irrespective of the cell line. The findings from this study offer insight into the pathogenic differences between H5N1 and H9N2 AIVs in varied hosts. Moreover, our findings can be used to help screen for host-specific anti-inflammatory agents.

The Clinical Value of GDF15 and Its Prospective Mechanism in Sepsis

Growth differentiation factor 15 (GDF15) is involved in the occurrence and development of many diseases, and there are few studies on its relationship with sepsis. This article aims to explore the clinical value of GDF15 in sepsis and to preliminarily explore its prospective regulatory effect on macrophage inflammation and its functions. We recruited 320 subjects (132 cases in sepsis group, 93 cases in nonsepsis group, and 95 cases in control group), then detected the serum GDF15 levels and laboratory indicators, and further investigated the correlation between GDF15 and laboratory indicators, and also analyzed the clinical value of GDF15 in sepsis diagnosis, severity assessment, and prognosis. In vitro, we used LPS to stimulate THP-1 and RAW264.7 cells to establish the inflammatory model, and detected the expression of GDF15 in the culture medium and cells under the inflammatory state. After that, we added GDF15 recombinant protein (rGDF15) pretreatment to explore its prospective regulatory effect on macrophage inflammation and its functions. The results showed that the serum GDF15 levels were significantly increased in the sepsis group, which was correlated with laboratory indexes of organ damage, coagulation indexes, inflammatory factors, and SOFA score. GDF15 also has a high AUC in the diagnosis of sepsis, which can be further improved by combining with other indicators. The dynamic monitoring of GDF15 levels can play an important role in the judgment and prognosis of sepsis. In the inflammatory state, the expression of intracellular and extracellular GDF15 increased. GDF15 can reduce the levels of cytokines, inhibit M1 polarization induced by LPS, and promote M2 polarization. Moreover, GDF15 also enhances the phagocytosis and bactericidal function of macrophages. Finally, we observed a decreased level of the phosphorylation of JAK1/STAT3 signaling pathway and the nuclear translocation of NF-κB p65 with the pretreatment of rGDF15. In summary, our study found that GDF15 has good clinical application value in sepsis and plays a protective role in the development of sepsis by regulating the functions of macrophages and inhibiting the activation of JAK1/STAT3 pathway and nuclear translocation of NF-κB p65.

Role of GDF-15, YKL-40 and MMP 9 in patients with end-stage kidney disease: focus on sex-specific associations with vascular outcomes and all-cause mortality

BACKGROUND

Sex differences are underappreciated in the current understanding of cardiovascular disease (CVD) in association with chronic kidney disease (CKD). A hallmark of CKD is vascular aging that is characterised, amongst others, by; systemic inflammation, microbiota disbalance, oxidative stress, and vascular calcification-features linked to atherosclerosis/arteriosclerosis development. Thus, it is the necessary to introduce novel biomarkers related to athero-/arteriosclerotic damage for better assessment of vascular ageing in patients CKD. However, little is known about the relationship between uraemia and novel CVD biomarkers, such as growth differentiation factor-15 (GDF-15), cartilage glycoprotein-39 (YKL-40) and matrix metalloproteinase-9 (MMP-9). Therefore, we hypothesise that there are sex-specific relationships between GDF-15, YKL-40, MMP-9 levels in end-stage kidney disease (ESKD) patients in relation to gut microbiota, vascular calcification, inflammation, comorbidities, and all-cause mortality.

METHODS

ESKD patients, males (n = 151) and females (n = 79), not receiving renal replacement therapy were selected from two ongoing prospective ESKD cohorts. GDF-15, YKL-40 and MMP9 were analysed using enzyme-linked immunosorbent assay kits. Biomarker levels were analysed in the context of gut microbiota-derived trimethylamine N-oxide (TMAO), vascular calcification, inflammatory response, oxidative stress, comorbidities, and all-cause mortality.

RESULTS

Increased GDF-15 correlated with higher TMAO in females only, and with higher coronary artery calcification and IL-6. In females, diabetes was associated with elevated GDF-15 and MMP-9, whilst males with diabetes only had elevated GDF-15. No associations were found between biomarkers and CVD comorbidity. Deceased males and females had higher GDF-15 concentrations (p = 0.01 and p < 0.001, respectively), meanwhile only YKL-40 was increased in deceased males (p = 0.02).

CONCLUSIONS

In conclusion, in males GDF-15 and YKL-40 were related to vascular calcification, inflammation, and oxidative stress, whilst in females GDF-15 was related to TMAO. Increased levels of YKL-40 and GDF-15 in males, and only GDF-15 in females, were associated with all-cause mortality. Our findings suggest that sex-specific associations of novel CVD biomarkers have a potential to affect development of cardiovascular complications in patients with ESKD.

Temporal changes and control variables of growth differentiation factor 15 levels during the first week of life in hospitalised newborn infants

Serum growth differentiation factor 15 (GDF15) is a useful biomarker of mitochondrial diseases; its utility in newborns remains unknown. To investigate the temporal change in GDF15 within the first week of life, and to identify its potential control variables, blood samples were obtained from 18 newborns. The GDF15 levels declined to approximately 35% of the cord blood levels within the first week of life and were negatively correlated with postnatal age and Z-score of birth weight but were positively correlated with N-terminal pro-brain natriuretic peptide and lactate levels. GDF15 levels may reflect the progress of postnatal transition to aerobic metabolism.

Cardiovascular disease related circulating biomarkers and cancer incidence and mortality: is there an association?

AIMS

Recent studies suggest an association between cardiovascular disease (CVD) and cancer incidence/mortality, but the pathophysiological mechanisms underlying these associations are unclear. We aimed to examine biomarkers previously associated with CVD and study their association with incident cancer and cancer-related death in a prospective cohort study.

METHODS AND RESULTS

We used a proteomic platform to measure 71 cardiovascular biomarkers among 5,032 participants in the Framingham Heart Study who were free of cancer at baseline. We used multivariable-adjusted Cox models to examine the association of circulating protein biomarkers with risk of cancer incidence and mortality. To account for multiple testing, we set a 2-sided false discovery rate (FDR Q-value) <0.05.Growth differentiation factor-15 (GDF15; also known as macrophage inhibitory cytokine-1 [MIC1])) was associated with increased risk of incident cancer (hazards ratio [HR] per 1 standard deviation increment 1.31, 95% CI 1.17-1.47), incident gastrointestinal cancer (HR 1.85, 95% CI 1.37-2.50), incident colorectal cancer (HR 1.94, 95% CI 1.29-2.91) and cancer-related death (HR 2.15, 95% CI 1.72-2.70). Stromal cell-derived factor-1 (SFD1) showed an inverse association with cancer-related death (HR 0.75, 95% CI 0.65-0.86). Fibroblast growth factor-23 (FGF23) showed an association with colorectal cancer (HR 1.55, 95% CI 1.20-2.00), and granulin (GRN) was associated with hematologic cancer (HR 1.61, 95% CI 1.30-1.99). Other circulating biomarkers of inflammation, immune activation, metabolism, and fibrosis showed suggestive associations with future cancer diagnosis.

CONCLUSION

We observed several significant associations between circulating CVD biomarkers and cancer, supporting the idea that shared biological pathways underlie both diseases. Further investigations of specific mechanisms that lead to both CVD and cancer are warranted.

TRANSLATIONAL PERSPECTIVE

In our prospective cohort study, baseline levels of biomarkers previously associated with CVD were found to be associated with future development of cancer. In particular, GDF15 was associated with increased risk of cancer incidence and mortality, including gastrointestinal and colorectal cancers; SDF1 was inversely associated with cancer-related death, and FGF23 and GRN were associated with increased risk of colorectal and hematologic cancers, respectively. Other biomarkers of inflammation, immune activation, metabolism, and fibrosis showed suggestive associations. These results suggest potential shared biological pathways that underlie both development of cancer and CVD.

Multidimensional Biomarker Analysis Including Mitochondrial Stress Indicators for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is accompanied by a complex and multifactorial pathogenesis with sequential progressions from inflammation to fibrosis and then to cancer. This heterogeneity interferes with the development of precise diagnostic and prognostic strategies for NAFLD. The current approach for the diagnosis of simple steatosis, steatohepatitis, and cirrhosis mainly consists of ultrasonography, magnetic resonance imaging, elastography, and various serological analyses. However, individual dry and wet biomarkers have limitations demanding an integrative approach for the assessment of disease progression. Here, we review diagnostic strategies for simple steatosis, steatohepatitis and hepatic fibrosis, followed by potential biomarkers associated with fat accumulation and mitochondrial stress. For mitochondrial stress indicators, we focused on fibroblast growth factor 21 (FGF21), growth differentiation factor 15 (GDF15), angiopoietin-related growth factor and mitochondrial-derived peptides. Each biomarker may not strongly indicate the severity of steatosis or steatohepatitis. Instead, multidimensional analysis of different groups of biomarkers based on pathogenic mechanisms may provide decisive diagnostic/prognostic information to develop a therapeutic plan for patients with NAFLD. For this purpose, mitochondrial stress indicators, such as FGF21 or GDF15, could be an important component in the multiplexed and contextual interpretation of NAFLD. Further validation of the integrative evaluation of mitochondrial stress indicators combined with other biomarkers is needed in the diagnosis/prognosis of NAFLD.

Roles and Regulation of Growth differentiation factor-15 in the Immune and tumor microenvironment

Growth differentiation factor-15 (GDF-15), a member of the TGF-β superfamily, plays multiple roles in a wide variety of cellular processes. It is expressed at low levels under normal conditions but is highly expressed in tumor and tumor microenvironment (TME)-related cells, such as fibroblasts and immune cells. The TME consists of the noncancerous cells present in the tumor, including immune cells, fibroblasts, blood vessel signaling molecules and extracellular matrix, which play a key role in tumor development. GDF-15 affects both stromal cells and immune cells in the TME. It also acts on immune checkpoints, such as PD-1/PDL-1 that regulate stemness of cancer cells, indicating that GDF-15 plays a prominent role in cancer, exhibiting both protumorigenic and antitumorigenic effects, although the latter are reported much less often than the former. The present review addresses novel ideas regarding communication between GDF-15 and stromal cells, immune cells, and cancer cells in the TME. In addition, it discusses the possibility of GDF-15's clinical application as a diagnostic biomarker and therapeutic target in cancer.

Current Use of Cardiac Biomarkers in Various Heart Conditions

Biomarkers are increasingly recognized to have significant clinical value in early identification and progression of various cardiovascular diseases. There are many heart conditions, such as congestive heart failure (CHF), ischemic heart diseases (IHD), and diabetic cardiomyopathy (DCM), and cardiac remodeling, in which the severity of the cardiac pathology can be mirrored through these cardiac biomarkers. From the emergency department (ED) evaluation of acute coronary syndromes (ACS) or suspected acute myocardial infarction (AMI) with cardiac marker Troponin to the diagnosis of chronic conditions like Heart Failure (HF) with natriuretic peptides, like B-type natriuretic peptide (BNP), N-terminal pro-B- type natriuretic peptide (Nt-proBNP) and mid regional pro-atrial natriuretic peptide (MR- proANP), their use is continuously increasing. Their clinical importance has led to the discovery of newer biomarkers, such as the soluble source of tumorigenicity 2 (sST2), galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15), and various micro ribonucleic acids (miRNAs). Since cardiac pathophysiology involves a complex interplay between inflammatory, genetic, neurohormonal, and biochemical levels, these biomarkers could be enzymes, hormones, and biologic substances showing cardiac injury, stress, and malfunction. Therefore, multi-marker approaches with different combinations of novel cardiac biomarkers, and continual assessment of cardiac biomarkers are likely to improve cardiac risk prediction, stratification, and overall patient wellbeing. On the other hand, these biomarkers may reflect coexisting or isolated disease processes in different organ systems other than the cardiovascular system. Therefore, knowledge of cardiac biomarkers is imperative. In this article, we have reviewed the role of cardiac biomarkers and their use in the diagnosis and prognosis of various cardiovascular diseases from different investigations conducted in recent years.

Novel methods to identify and measure catabolism

PURPOSE OF REVIEW

Assess current potential catabolism-biomarkers to characterize patients developing prolonged critical illness.

RECENT FINDINGS

A raised urea-to-creatinine ratio (UCR) during critical illness is negatively associated with muscle mass with greater increases in UCR seen patients developing persistent critical illness. Similarly, sarcopenia index (a ratio of creatinine to cystatin-c concentrations) correlates well to muscle mass in intensive care populations. Elevated growth/differentiation factor-15 (GDF-15) has been inconsistently associated with muscle loss. Although GDF-15 was a poor marker of feeding tolerance, it has been associated with worse prognosis in intensive care.

SUMMARY

UCR is an available and clinically applicable biomarker of catabolism. Similarly, sarcopenia index can be used to assess muscle mass and indirectly measure catabolism based on readily available biochemical measurements. The utility of novel biomarkers, such as GDF-15 is less established.

Acidosis-induced activation of distal nephron principal cells triggers Gdf15 secretion and adaptive proliferation of intercalated cells

AIM

Type A intercalated cells of the renal collecting duct participate in the maintenance of the acid/base balance through their capacity to adapt proton secretion to homeostatic requirements. We previously showed that increased proton secretion stems in part from the enlargement of the population of proton secreting cells in the outer medullary collecting duct through division of fully differentiated cells, and that this response is triggered by growth/differentiation factor 15. This study aimed at deciphering the mechanism of acid load-induced secretion of Gdf15 and its mechanism of action.

METHODS

We developed an original method to evaluate the proliferation of intercalated cells and applied it to genetically modified or pharmacologically treated mice under basal and acid-loaded conditions.

RESULTS

Gdf15 is secreted by principal cells of the collecting duct in response to the stimulation of vasopressin receptors. Vasopressin-induced production of cAMP triggers activation of AMP-stimulated kinases and of Na,K-ATPase, and induction of p53 and Gdf15. Gdf15 action on intercalated cells is mediated by ErbB2 receptors, the activation of which triggers the expression of cyclin d1, of p53 and anti-proliferative genes, and of Egr1.

CONCLUSION

Acidosis-induced proliferation of intercalated cells results from a cross talk with principal cells which secrete Gdf15 in response to their stimulation by vasopressin. Thus, vasopressin is a major determinant of the collecting duct cellular homeostasis as it promotes proliferation of intercalated cells under acidosis conditions and of principal cells under normal acid-base status.

Activation of the hypothalamic-pituitary-adrenal axis by exogenous and endogenous GDF15

An acute increase in the circulating concentration of glucocorticoid hormones is essential for the survival of severe somatic stresses. Circulating concentrations of GDF15, a hormone that acts in the brain to reduce food intake, are frequently elevated in stressful states. We now report that GDF15 potently activates the hypothalamic-pituitary-adrenal (HPA) axis in mice and rats. A blocking antibody to the GDNF-family receptor α-like receptor completely prevented the corticosterone response to GDF15 administration. In wild-type mice exposed to a range of stressful stimuli, circulating levels of both corticosterone and GDF15 rose acutely. In the case of Escherichia coli or lipopolysaccharide injections, the vigorous proinflammatory cytokine response elicited was sufficient to produce a near-maximal HPA response, regardless of the presence or absence of GDF15. In contrast, the activation of the HPA axis seen in wild-type mice in response to the administration of genotoxic or endoplasmic reticulum toxins, which do not provoke a marked rise in cytokines, was absent in Gdf15 ^-/- mice. In conclusion, consistent with its proposed role as a sentinel hormone, endogenous GDF15 is required for the activation of the protective HPA response to toxins that do not induce a substantial cytokine response. In the context of efforts to develop GDF15 as an antiobesity therapeutic, these findings identify a biomarker of target engagement and a previously unrecognized pharmacodynamic effect, which will require monitoring in human studies.

Circulating growth differentiation factor-15 as a novel biomarker in heart transplant

Aims

This study aimed to examine (i) whether circulating growth differentiation factor‐15 (GDF‐15) is associated with acute cellular cardiac allograft rejection (ACR); (ii) a longitudinal trend of GDF‐15 after heart transplantation; and (iii) the prognostic value of GDF‐15 in predicting a composite outcome of severe primary graft dysfunction (PGD) and 30 day mortality post‐transplant.

Methods and results

Serum samples were collected before heart transplantation and at every endomyocardial biopsy (EMB) post‐heart transplantation in de novo transplant patients. A total of 60 post‐transplant serum samples were matched to the corresponding EMBs. Seven (12%) were considered International Society for Heart Lung Transplantation Grade 1R ACR, and one (2%) was identified as Grade 2R ACR. GDF‐15 levels in patients with ACR were not different from those in the non‐rejection group (6230 vs. 6125 pg/mL, P = 0.27). GDF‐15 concentration gradually decreased from 8757 pg/mL pre‐transplant to 5203 pg/mL at 4 weeks post‐transplant. The composite adverse outcome of PGD and 30 day mortality was significantly associated with increased post‐operative GDF‐15 (odds ratio: 40; 95% confidence interval: 2.01–794.27; P = 0.005) and high inotrope score post‐transplant (odds ratio: 18; 95% confidence interval: 1.22–250.35; P = 0.01).

Conclusions

Circulating GDF‐15 concentration was markedly elevated in patients with end‐stage heart failure and decreased after heart transplantation. GDF‐15 was significantly associated with post‐transplant PGD and mortality. A lack of association between ACR and GDF‐15 did not support routine use of GDF‐15 as a biomarker to detect ACR. However, GDF‐15 may be potentially useful to determine heart transplant recipients at high risk for adverse post‐transplant outcomes. We suggest that GDF‐15 levels in recipient serum can provide risk stratification for severe PGD including death during post‐operative period. This novel biomarker may serve to inform and guide timely interventions against severe PGD and adverse outcomes during the first 4 weeks after transplantation. Further studies to support the utility of GDF‐15 in heart transplantation are required.