Dipeptidyl peptidase 3, a marker of the antagonist pathway of the renin-angiotensin-aldosterone system in patients with heart failure

Shock prediction with dipeptidyl peptidase-3 and renin (SPiDeR) in hypoxemic patients with COVID-19

BACKGROUND

Plasma dipeptidyl peptidase-3 (DPP3) and renin levels are associated with organ dysfunction and mortality. However, whether these biomarkers are associated with the subsequent onset of shock in at-risk patients is unknown.

METHODS

Using plasma samples collected from participants enrolled in the fourth Accelerating COVID-19 Therapeutic Interventions and Vaccines Host Tissue platform trial, we measured DPP3 and renin in 184 subjects hospitalized with acute hypoxemia from COVID-19 without baseline vasopressor requirement. We calculated the odds ratio of development of shock (defined as the initiation of vasopressor therapy) by Day 28 based on Day 0 DPP3 and renin levels.

RESULTS

Subjects with DPP3 above the median had a significantly higher incidence of vasopressor initiation within 28 days (28.4 % vs. 16.7 %, p = 0.031) and higher 28-day mortality (25.0 % vs. 6.7 %, p < 0.001). After adjusting for covariables, DPP3 above the median was associated with shorter time to vasopressor initiation, greater 28-day mortality, fewer vasopressor-free days, and greater odds of a hypotensive event over 7 days. Significant associations were not observed for renin.

CONCLUSIONS

In patients hospitalized with COVID-19 and hypoxemia without baseline hypotension, higher baseline plasma levels of DPP3 but not renin were associated with increased risk of subsequent shock and death.

Identifying biomarker-driven subphenotypes of cardiogenic shock: analysis of prospective cohorts and randomized controlled trials

Background

Cardiogenic shock (CS) is a heterogeneous clinical syndrome, making it challenging to predict patient trajectory and response to treatment. This study aims to identify biological/molecular CS subphenotypes, evaluate their association with outcome, and explore their impact on heterogeneity of treatment effect (ShockCO-OP, NCT06376318).

Methods

We used unsupervised clustering to integrate plasma biomarker data from two prospective cohorts of CS patients: CardShock (N = 205 [2010-2012, NCT01374867]) and the French and European Outcome reGistry in Intensive Care Units (FROG-ICU) (N = 228 [2011-2013, NCT01367093]) to determine the optimal number of classes. Thereafter, a simplified classifier (Euclidean distances) was used to assign the identified CS subphenotypes in three completed randomized controlled trials (RCTs) (OptimaCC, N = 57 [2011-2016, NCT01367743]; DOREMI, N = 192 [2017-2020, NCT03207165]; and CULPRIT-SHOCK, N = 434 [2013-2017, NCT01927549]) and explore heterogeneity of treatment effect with respect to 28-day mortality (primary outcome).

Findings

Four biomarker-driven CS subphenotypes ('adaptive', 'non-inflammatory', 'cardiopathic', and 'inflammatory') were identified separately in the two cohorts. Patients in the inflammatory and cardiopathic subphenotypes had the highest 28-day mortality (p (log-rank test) = 0.0099 and 0.0055 in the CardShock and FROG-ICU cohorts, respectively). Subphenotype membership significantly improved risk stratification when added to traditional risk factors including the Society for Cardiovascular Angiography and Interventions (SCAI) shock stages (increase in Harrell's C-index by 4% (p = 0.033) and 6% (p = 0.0068) respectively in the CardShock and the FROG-ICU cohorts). The simplified classifier identified CS subphenotypes with similar biological/molecular and outcome characteristics in the three independent RCTs. No significant interaction was observed between treatment effect and subphenotypes.

Interpretation

Subphenotypes with the highest concentration of biomarkers of endothelial dysfunction and inflammation (inflammatory) or myocardial injury/fibrosis (cardiopathic) were associated with mortality independently from the SCAI shock stages.

Funding

Dr Sabri Soussi was awarded the Canadian Institutes of Health Research (CIHR) Doctoral Foreign Study Award (DFSA) and the Merit Awards Program (Department of Anesthesiology and Pain Medicine, University of Toronto, Canada) for the current study.

Dipeptidyl peptidase 3 plasma levels predict cardiogenic shock and mortality in acute coronary syndromes

BACKGROUND AND AIMS

Dipeptidyl peptidase 3 (DPP3) is a protease involved in the degradation of angiotensin II which disturbs peripheral blood pressure regulation and compromises left ventricular function. This study examined the relationship of circulating DPP3 (cDPP3) with cardiogenic shock (CS) and mortality in patients presenting with acute coronary syndromes (ACS).

METHODS

Plasma cDPP3 levels were assessed at baseline and 12-24 h after presentation in patients with ACS prospectively enrolled into the multi-centre SPUM-ACS study (n = 4787).

RESULTS

Circulating DPP3 levels were associated with in-hospital CS when accounting for established risk factors including the ORBI risk score [per log-2 increase, hazard ratio (HR) 1.38, 95% confidence interval (CI) 1.05-1.82, P = .021]. High cDPP3 was an independent predictor of mortality at 30 days (HR 1.87, 95% CI 1.36-2.58, P < .001) and at one year (HR 1.61, 95% CI 1.28-2.02, P < .001) after adjustment for established risk factors and the GRACE 2.0 score. Compared to values within the normal range, persistently elevated cDPP3 levels at 12-24 h were associated with 13.4-fold increased 30-day mortality risk (HR 13.42, 95% CI 4.86-37.09, P < .001) and 5.8-fold increased 1-year mortality risk (HR 5.79, 95% CI 2.70-12.42, P < .001). Results were consistent across various patient subgroups.

CONCLUSIONS

This study identifies cDPP3 as a novel marker of CS and increased mortality in patients with ACS. Circulating DPP3 offers prognostic information beyond established risk factors and improves early risk assessment.

Post-myocardial infarction fibrosis: Pathophysiology, examination, and intervention

Cardiac fibrosis plays an indispensable role in cardiac tissue homeostasis and repair after myocardial infarction (MI). The cardiac fibroblast-to-myofibroblast differentiation and extracellular matrix collagen deposition are the hallmarks of cardiac fibrosis, which are modulated by multiple signaling pathways and various types of cells in time-dependent manners. Our understanding of the development of cardiac fibrosis after MI has evolved in basic and clinical researches, and the regulation of fibrotic remodeling may facilitate novel diagnostic and therapeutic strategies, and finally improve outcomes. Here, we aim to elaborate pathophysiology, examination and intervention of cardiac fibrosis after MI.

Heart failure: an update from the last years and a look at the near future

In the last years, major progress occurred in heart failure (HF) management. Quadruple therapy is now mandatory for all the patients with HF with reduced ejection fraction. Whilst verciguat is becoming available across several countries, omecamtiv mecarbil is waiting to be released for clinical use. Concurrent use of potassium-lowering agents may counteract hyperkalaemia and facilitate renin-angiotensin-aldosterone system inhibitor implementations. The results of the EMPagliflozin outcomE tRial in Patients With chrOnic heaRt Failure With Preserved Ejection Fraction (EMPEROR-Preserved) trial were confirmed by the Dapagliflozin in Heart Failure with Mildly Reduced or Preserved Ejection Fraction (DELIVER) trial, and we now have, for the first time, evidence for treatment of also patients with HF with preserved ejection fraction. In a pre-specified meta-analysis of major randomized controlled trials, sodium-glucose co-transporter-2 inhibitors reduced all-cause mortality, cardiovascular (CV) mortality, and HF hospitalization in the patients with HF regardless of left ventricular ejection fraction. Other steps forward have occurred in the treatment of decompensated HF. Acetazolamide in Acute Decompensated Heart Failure with Volume Overload (ADVOR) trial showed that the addition of intravenous acetazolamide to loop diuretics leads to greater decongestion vs. placebo. The addition of hydrochlorothiazide to loop diuretics was evaluated in the CLOROTIC trial. Torasemide did not change outcomes, compared with furosemide, in TRANSFORM-HF. Ferric derisomaltose had an effect on the primary outcome of CV mortality or HF rehospitalizations in IRONMAN (rate ratio 0.82; 95% confidence interval 0.66-1.02; P = 0.070). Further options for the treatment of HF, including device therapies, cardiac contractility modulation, and percutaneous treatment of valvulopathies, are summarized in this article.

DPP3: From biomarker to therapeutic target of cardiovascular diseases

Cardiovascular disease is the leading cause of death globally among non-communicable diseases, which imposes a serious socioeconomic burden on patients and the healthcare system. Therefore, finding new strategies for preventing and treating cardiovascular diseases is of great significance in reducing the number of deaths and disabilities worldwide. Dipeptidyl peptidase 3 (DPP3) is the first zinc-dependent peptidase found among DPPs, mainly distributes within the cytoplasm. With the unique HEXXGH catalytic sequence, it is associated with the degradation of oligopeptides with 4 to 10 amino acids residues. Accumulating evidences have demonstrated that DPP3 plays a significant role in almost all cellular activities and pathophysiological mechanisms. Regarding the role of DPP3 in cardiovascular diseases, it is currently mainly used as a biomarker for poor prognosis in patients with cardiovascular diseases, suggesting that the level of DPP3 concentration in plasma is closely linked to the mortality of diseases such as cardiogenic shock and heart failure. Interestingly, it has been reported recently that DPP3 regulates blood pressure by interacting with the renin-angiotensin system. In addition, DPP3 also participates in the processes of pain signaling, inflammation, and oxidative stress. But the exact mechanism by which DPP3 affects cardiovascular function is not clear. Hence, this review summarizes the recent advances in the structure and catalytic activity of DPP3 and its extensive biological functions, especially its role as a therapeutic target in cardiovascular diseases. It will provide a theoretical basis for exploring the potential value of DPP3 as a therapeutic target for cardiovascular diseases.

Dipeptidyl Peptidase 3 Activity as a Promising Biomarker of Bone Fragility in Postmenopausal Women

The dipeptidyl peptidase 3 (Dpp3) is a ubiquitous zinc-dependent aminopeptidase, participating in the activation or degradation of signaling peptides and in the Keap1−Nrf2 antioxidant pathway. The absence of Dpp3 in the Dpp3 knockout mouse model causes increased osteoclast activity, altered osteogenic function, sustained oxidative stress in the bone tissue, and bone loss. We aimed to assess the association of Dpp3 activity with bone fragility in postmenopausal osteoporosis and the impact of denosumab on enzymatic activity. We conducted a two-phase study including 69 postmenopausal women with severe osteoporosis and 36 postmenopausal women without osteometabolic conditions, as controls (cross-sectional phase). Subjects with severe osteoporosis were assessed at baseline and 14 days after the first denosumab administration (prospective phase). The results showed significant reduction in serum Dpp3 activity (expressed as nmoles of formed product/mg proteins/min) in patients vs. controls (0.791 ± 0.232 vs. 1.195 ± 0.338; p < 0.001), and significant association with bone mass at the femoral neck (r = 0.28, p = 0.02) in patients prior to treatment. We found a negative correlation between C-terminal telopeptide (CTX) or N-terminal pro-peptide of type 1 procollagen (P1NP) levels and Dpp3 activity (respectively, r = −0.29, p = 0.012; and r = −0.2572, p = 0.033). Dpp3 activity did not change after denosumab injection. Our findings support a critical role played by Dpp3 in bone homeostasis as a potential bone protective factor. Additional clinical studies in larger cohorts might explore the implementation of Dpp3 assessment as a biomarker of bone health status.

Dipeptidylamino-tripeptidylcarboxypeptidase NEMP3 and DPP3 (DPP III) are the same protein

Earlier it was shown that a group of extracellular low-specific metallopeptidases is present in the mammalian brain Kropotova and Mosevitsky (2016) [1]. These enzymes are weakly connected to the axonal ends of neurons. They were named Neuron bound Extracellular MetalloPeptidases (NEMP). The enzyme named NEMP3 turned out to be a unique exopeptidase that exhibits two activities: it removes the dipeptide from the N-end of the peptide, and it can also remove the tripeptide from the C-end of the peptide. Therefore, NEMP3 possesses the activities of dipeptidylaminopeptidase and of tripeptidylcarboxypeptidase. Mass spectrometry has revealed a homology of NEMP3 with DPP3 (DPP III, EC3.4.14.4), known as cytosolic dipeptidylaminopeptidase. We isolated DPP3 from rat and bovine liver and brain by the procedures used for this purpose by other authors. The effect of DPP3 on test peptides is the same as that of NEMP3. In particular, all DPP3 samples delete the tripeptide (AKF) from the C-end of the test peptide blocked at the N-end. The data obtained show that NEMP3 and DPP3 are the same protein (enzyme). Thus, DPP3 has two exopeptidase activities: the previously known activity of dipeptidylaminopeptidase and the activity of tripeptidylcarboxypeptidase discovered in this study. Another discovery is the extracellular activity of DPP 3 in the mammalian brain near synapses, which controls neuropeptides. DPP3 is involved in various processes, but in many cases its role remains to be clarified. The results obtained in this study will be useful for solving these questions.