Heads and Tails of Natriuretic Peptides: Neuroprotective Role of Brain Natriuretic Peptide

Serum Soluble Corin and Long-Term Clinical Outcomes After Acute Ischemic Stroke

BACKGROUND

Corin plays important roles in the regulation of blood volume and pressure and cardiac function by activating natriuretic peptide pathway, exerting multiple cardioprotective effects. But the impacts of soluble corin on clinical outcomes after ischemic stroke are unclear. We aimed to investigate the associations between serum soluble corin and long-term clinical outcomes after acute ischemic stroke.

METHODS AND RESULTS

We measured the concentrations of serum soluble corin in 3162 participants (2010 men and 1152 women) from the China Antihypertensive Trial in Acute Ischemic Stroke. The clinical outcomes were recurrent stroke, cardiovascular events, all-cause mortality, and unfavorable functional outcome within 24 months after stroke. Risk reclassification for study clinical outcomes of models with soluble corin were evaluated. Serum soluble corin was inversely associated with recurrent stroke, cardiovascular events, and unfavorable functional outcome after ischemic stroke. After adjusting for multiple covariates, each additional SD of log-corin was associated with a 21% (95% CI, 11-30), 16% (95% CI, 6-26), and 12% (95% CI, 3-21) decreased risk for recurrent stroke, cardiovascular events, and unfavorable functional outcome, respectively. Furthermore, the addition of soluble corin to the basic model with conventional risk factors significantly improved risk discrimination for recurrent stroke, cardiovascular events, and the composite outcome of all-cause mortality and cardiovascular events, as shown by C-statistics (all P<0.05).

CONCLUSIONS

Serum soluble corin was associated with decreased risks of long-term clinical outcomes, and may be a promising prognostic biomarker for risk stratification in patients with acute ischemic stroke.

High brain natriuretic peptide level is associated with severe stroke in patients taking oral anticoagulants: A sub-analysis of the PASTA registry study

BACKGROUND

Brain natriuretic peptides (BNP) are an important diagnostic and prognostic marker in patients with heart failure. However, the relationship between BNP levels and stroke severity in patients with atrial fibrillation (AF) remains unelucidated. In this study, we aimed to investigate the association between stroke severity at admission and BNP levels.

METHODS

In this prospective observational study, we used data from 513 patients with AF and acute ischemic stroke treated with oral anticoagulants (OAC) registered in the Multicenter Prospective Analysis of Stroke Patients Taking Oral Anticoagulants study. The patients were divided into two groups: high-BNP (≥200 pg/mL) and low-BNP level (<200 pg/mL) groups. We compared the clinical characteristics between the two groups and determined the effect of BNP levels on stroke severity on admission.

RESULTS

Among the 513 enrolled patients, 248 (females, n = 30; median age, 82 years) and 265 (females, n = 76; median age, 71 years) were assigned to the high- and low-BNP level groups, respectively. The high-BNP level group had a higher proportion of patients with severe stroke (National Institutes of Health Stroke Scale score, ≥10) on admission (49.2% vs. 32.8%, p = 0.002) and major vessel occlusion (57.5% vs. 39.2%, p < 0.0001) than that had by the low-BNP level group. Multivariate analysis showed that high BNP level was independently associated with severe stroke on admission (odds ratio 1.07, 95% confidence interval 1.00-1.15; p = 0.0478).

CONCLUSIONS

High BNP level compared with low BNP level was associated with severe stroke and major vessel occlusion, even before OAC treatment.

Associations of B-Type Natriuretic Peptide and Its Coding Gene Promoter Methylation With Functional Outcome of Acute Ischemic Stroke: A Mediation Analysis

Background

The prognostic role of B‐type natriuretic peptide (BNP) in stroke has been suggested, but limited studies have shown mixed results and unknown underlying mechanisms. DNA methylation, a molecular modification that alters gene expression, may represent a candidate mechanism for this purpose. We aimed to examine the associations of BNP and methylation of its coding gene (natriuretic peptide B [NPPB]) with the functional outcome in a large sample of patients with acute ischemic stroke from CATIS (China Antihypertensive Trial in Acute Ischemic Stroke).

Methods and Results

Leveraging participants from CATIS with available specimens, serum proBNP (equimolarly produced with BNP) was measured in 3216 patients (mean age, 62 years; 64% men), and peripheral blood DNA methylation of the NPPB promoter was quantified by targeted bisulfite sequencing in 806 patients (mean age, 62 years; 54% men). The functional outcome was defined as an ordered modified Rankin Scale score assessed at 14 days or hospital discharge after stroke onset. Mediation analysis was conducted to test the potential mediating effect of proBNP on the relationship between NPPB methylation and functional outcome. The results showed that a higher level of proBNP was significantly associated with a higher risk of having a poorer functional outcome (odds ratio [OR], 1.14; P=0.006). Every 5% of hypermethylation at 2 (Chr1:11919160 [OR, 0.93; P=0.022] and Chr1:11918989 [OR, 0.92; P=0.032]) of 11 CpG loci assayed was associated with 7% and 8% lower risk, respectively, of having a poor functional outcome. In addition, proBNP was negatively correlated to hypermethylation at 1 CpG (Chr1:11918989 [β=−0.029; P=0.009]) and mediated approximately 7.69% (95% CI, 2.50%–13.82%) of the association between this CpG methylation and the functional outcome.

Conclusions

Hypermethylation at the NPPB promoter is associated with the functional outcome after ischemic stroke, at least partially by suppressing BNP expression or excretion.

Natriuretic Peptides, Cognitive Impairment and Dementia: An Intriguing Pathogenic Link with Implications in Hypertension

The natriuretic peptides (NPs) belong to a family of cardiac hormones that exert relevant protective functions within the cardiovascular system. An increase of both brain and atrial natriuretic peptide levels, particularly of the amino-terminal peptides (NT-proBNP and NT-proANP), represents a marker of cardiovascular damage. A link between increased NP levels and cognitive decline and dementia has been reported in several human studies performed both in general populations and in cohorts of patients affected by cardiovascular diseases (CVDs). In particular, it was reported that the elevation of NP levels in dementia can be both dependent and independent from CVD risk factors. In the first case, it may be expected that, by counteracting early on the cardiovascular risk factor load and the pathological processes leading to increased aminoterminal natriuretic peptide (NT-proNP) level, the risk of dementia could be significantly reduced. In case of a link independent from CVD risk factors, an increased NP level should be considered as a direct marker of neuronal damage. In the context of hypertension, elevated NT-proBNP and mid-regional (MR)-proANP levels behave as markers of brain microcirculatory damage and dysfunction. The available evidence suggests that they could help in identifying those subjects who would benefit most from a timely antihypertensive therapy.

Therapeutic effects of recombinant human brain natriuretic peptide on sepsis-associated encephalopathy in mice

There is little information in the sepsis treatment guidelines on the prevention and treatment of cognitive dysfunction after sepsis. This study aimed to explore whether Recombinant human brain natriuretic peptide (rhBNP) has protective effects against sepsis-associated encephalopathy (SAE) in a mouse model. The results showed that 50 μg/kg of rhBNP significantly improved the 14-day survival of cecal ligation and puncture (CLP)-induced septic mice and mitigated cognitive dysfunction and anxiety. Fourteen days after CLP surgery, septic mice showed increased BBB permeability and neuronal apoptosis. rhBNP treatment significantly reduced pathological changes in the brain of CLP mice. Meanwhile, rhBNP therapy also reduced the level of inflammatory cytokines in the hippocampus, possibly via inhibiting the TLR4-NF-κB pathway. These results indicate that rhBNP may be a promising drug for the treatment of SAE.

The effect of antecedent-conditioning high-intensity interval training on BDNF regulation through PGC-1α pathway following cerebral ischemia

Earlier studies have demonstrated that exercise training can result in the diminishing of ischemic stroke-induced damages as well as BDNF misregulation. However, the underlying mechanisms of BDNF changes in response to ischemic stroke and exercise are still not entirely understood. Therefore, the aim of the current study was to determine whether high-intensity interval training (HIIT) in hippocampus of rat model of ischemic stroke intercedes PPARγ coactivator 1α (PGC1α)-pathway factors and BDNF regulation following induction of ischemic stroke. For this purpose, in this study, induction of middle cerebral artery occlusion (MCAO) was accomplished following the completion of HIIT. To define the molecular mechanisms that might be responsible for HIIT-associated improvements subsequent to cerebral ischemia, we likewise evaluated PGC-1α-pathway factors that may be essential for BDNF upregulation after MCAO via immunofluorescence tracking and ELISA immunoassay. Taking our findings together, three weeks of antecedent-HIIT resulted in more expression and delivery of BDNF in brain and plasma following MCAO through PGC-1α-pathway (p < 0.05). The present investigation also found a close relationship between expressed PGC-1α-pathway factors in brain and their concentrations in plasma (p < 0.05). In conclusion, findings of the current study exhibited that induction of cerebral ischemia as well as HIIT intervention both were associated with expression of PGC-1α-pathway factors in brain and their deliverance to blood. Consequently, these alterations may be considered as a protective factor against post-stroke neurological and functional disorders in the stroke model.