Rationale and Design of the Groningen Intervention Study for the Preservation of Cardiac Function with Sodium Thiosulfate after St-segment Elevation Myocardial Infarction (GIPS-IV) trial

Correlation between prognosis and peripheral blood levels of NLRP3 and triglyceride-glucose index after myocardial ischemia-reperfusion injury

OBJECTIVE

We aim to investigate the association between prognosis and outcomes following myocardial ischemia-reperfusion injury, as well as peripheral blood levels of NLRP3 and the triglyceride-glucose index (TyG).

METHODS

A total of 100 patients who underwent emergency coronary intervention following myocardial infarction confirmed by coronary angiography at our hospital between October 2021 and May 2023 were included in this study. Patients were stratified into two groups based on their prognoses: the control group (n = 73), which did not experience new myocardial infarctions or require hospitalization for heart failure or suffer sudden cardiac death post-interventional treatment; and the observation group (n = 27), which experienced one or more cardiovascular events post-treatment. Patient demographics were obtained from clinical records while biochemical analyses assessed peripheral blood triglycerides, blood glucose levels, and TyG index. Additionally, ELISA measurements determined levels of NLRP3 as well as inflammatory factors IL-6, TNF-α, and CRP in peripheral blood samples. Cardiac function was evaluated according to NYHA standards. Univariable Cox regression analysis identified factors influencing patient prognosis while Pearson correlation analysis examined relationships among prognosis, outcomes following myocardial ischemia-reperfusion injury, TyG index, and peripheral blood NLRP3.

RESULTS

No significant differences were observed in the general characteristics between the two patient groups (P > 0.05). However, the observation group exhibited higher levels of peripheral blood triglycerides, blood glucose, and TyG index compared to the control group (P < 0.05). Additionally, levels of NLRP3 and inflammatory factors IL-6, TNF-α, and CRP were elevated in the observation group compared to the control group (P < 0.05). Cardiac function impairment was more pronounced in the observation group (P < 0.05). Notably, TyG index and peripheral blood NLRP3 demonstrated higher risk ratios compared to other biomarkers (P < 0.05), indicating their significance in prognosis and outcomes. Elevated levels of NLRP3 and TyG index were associated with poorer recovery of cardiac function, increased rehospitalization rates, and higher mortality (P < 0.05).

CONCLUSION

Elevated NLRP3 levels and an increased TyG index are strongly associated with impaired cardiac function and heightened risk of cardiovascular events. These findings suggest that these biomarkers may serve as crucial prognostic indicators following myocardial ischemia-reperfusion injury.

Gasotransmitter Research Advances in Respiratory Diseases

Significance: Gasotransmitters are small gas molecules that are endogenously generated and have well-defined physiological functions. The most well-defined gasotransmitters currently are nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S), while other potent gasotransmitters include ammonia, methane, cyanide, hydrogen gas, and sulfur dioxide. Gasotransmitters play a role in various respiratory diseases such as asthma, chronic obstructive pulmonary disease, obstructive sleep apnea, lung infection, bronchiectasis, cystic fibrosis, primary ciliary dyskinesia, and COVID-19. Recent Advances: Gasotransmitters can act as biomarkers that facilitate disease diagnosis, indicate disease severity, predict disease exacerbation, and evaluate disease outcomes. They also have cell-protective properties, and many studies have been conducted to explore their pharmacological applications. Innovative drug donors and drug delivery methods have been invented to amplify their therapeutic effects. Critical Issues: In this article, we briefly reviewed the physiological and pathophysiological functions of some gasotransmitters in the respiratory system, the progress in detecting exhaled gasotransmitters, as well as innovative drugs derived from these molecules. Future Directions: The current challenge for gasotransmitter research includes further exploring their physiological and pathological functions, clarifying their complicated interactions, exploring suitable drug donors and delivery devices, and characterizing new members of gasotransmitters. Antioxid. Redox Signal. 40, 168-185.

Biomimetic Grapefruit-Derived Extracellular Vesicles for Safe and Targeted Delivery of Sodium Thiosulfate against Vascular Calcification

As the prevalence of vascular calcification (VC), a strong contributor to cardiovascular morbidity and mortality, continues to increase, the need for pharmacologic therapies becomes urgent. Sodium thiosulfate (STS) is a clinically approved drug for therapy against VC; however, its efficacy is hampered by poor bioavailability and severe adverse effects. Plant-derived extracellular vesicles have provided options for VC treatment since they can be used as biomimetic drug carriers with higher biosafety and targeting abilities than artificial carriers. Inspired by natural grapefruit-derived extracellular vesicles (EVs), we fabricated a biomimetic nanocarrier comprising EVs loaded with STS and further modified with hydroxyapatite crystal binding peptide (ESTP) for VC-targeted delivery of STS. In vitro, the ESTP nanodrug exhibited excellent cellular uptake capacity by calcified vascular smooth muscle cells (VSMCs) and subsequently inhibited VSMCs calcification. In the VC mice model, the ESTP nanodrug showed preferentially the highest accumulation in the calcified arteries compared to other treatment groups. Mechanistically, the ESTP nanodrug significantly prevented VC via driving M2 macrophage polarization, reducing inflammation, and suppressing bone-vascular axis as demonstrated by inhibiting osteogenic phenotype trans-differentiation of VSMCs while enhancing bone quality. In addition, the ESTP nanodrug did not induce hemolysis or cause any damage to other organs. These results suggest that the ESTP nanodrug can prove to be a promising agent against VC without the concern of systemic toxicity.

Diabetes Mellitus in Acute Coronary Syndrome

The global prevalence of diabetes mellitus (DM) has led to a pandemic, with significant microvascular and macrovascular complications including coronary artery disease (CAD), which worsen clinical outcomes and cardiovascular prognosis. Patients with both acute coronary syndrome (ACS) and DM have worse prognosis and several pathophysiologic mechanisms have been implicated including, insulin resistance, hyperglycemia, endothelial dysfunction, platelet activation and aggregations as well as plaque characteristics and extent of coronary lesions. Therefore, regarding reperfusion strategies in the more complex anatomies coronary artery bypass surgery may be the preferred therapeutic strategy over percutaneous coronary intervention while both hyperglycemia and hypoglycemia should be avoided with closed monitoring of glycemic status during the acute phase of myocardial infraction. However, the best treatment strategy remains undefined. Non-insulin therapies, due to the low risk of hypoglycemia concurrently with the multifactorial CV protective effects, may be proved to be the best treatment option in the future. Nevertheless, evidence for the beneficial effects of glucagon like peptide-1 receptor agonists, dipeptidyl-peptidase 4 inhibitors and sodium glycose cotransporter 2 inhibitors, despite accumulating, is not robust and future randomized control trials may provide more definitive data.

Associations of systemic oxidative stress with functional outcomes after ST-segment elevation myocardial infarction

BACKGROUND

Ischemia-reperfusion is accompanied by oxidative stress. Serum free thiols (FTs; sulfhydryl groups) reliably reflect systemic oxidative stress. This study evaluates longitudinal changes in FTs and their associations with outcomes after ST-segment elevation myocardial infarction (STEMI).

METHODS

FTs were detected in archived serum samples from 378 participants of a neutral randomized trial on metformin therapy after STEMI. FT levels were determined at presentation with STEMI and at 24 h, 2 weeks, 4 months and 1 year thereafter. Outcomes included infarct size and left ventricular ejection fraction (LVEF), both determined with cardiac magnetic resonance imaging after 4 months, and 5-year major adverse cardiovascular events (MACE).

RESULTS

Serum FT concentrations at presentation and at 24 h were 356 ± 91 and 353 ± 76 μmol/L, respectively. The change in FTs between presentation and 24 h (ΔFTs) was associated with outcomes in age- and sex-adjusted analysis (per 100 μmol/L FT increase, β = -0.87 for infarct size, 95% confidence interval (CI): -1.75 to -0.001, P = 0.050; β = 1.31, 95% CI: 0.37 to 2.25 for LVEF, P = 0.007). Associations between ΔFTs and LVEF were markedly stronger in patients with Thrombolysis in Myocardial Infarction flow of 0 or 1 before percutaneous coronary intervention (PCI)(β = 2.73, 95% CI: 0.68 to 4.77, P = 0.009). Declining FTs during the first 24 h might be associated with higher incidence of 5-year MACE (P = 0.09).

CONCLUSIONS

Changes in oxidative stress early post-PCI may predict functional outcomes after STEMI. Our findings warrant validation in larger cohorts, and then may be used as rationale for development of thiol-targeted therapy in ischemic heart disease.

Modulation of the nitric oxide/cGMP pathway in cardiac contraction and relaxation: Potential role in heart failure treatment

Evidence exists that heart failure (HF) has an overall impact of 1-2 % in the global population being often associated with comorbidities that contribute to increased disease prevalence, hospitalization, and mortality. Recent advances in pharmacological approaches have significantly improved clinical outcomes for patients with vascular injury and HF. Nevertheless, there remains an unmet need to clarify the crucial role of nitric oxide/cyclic guanosine 3',5'-monophosphate (NO/cGMP) signalling in cardiac contraction and relaxation, to better identify the key mechanisms involved in the pathophysiology of myocardial dysfunction both with reduced (HFrEF) as well as preserved ejection fraction (HFpEF). Indeed, NO signalling plays a crucial role in cardiovascular homeostasis and its dysregulation induces a significant increase in oxidative and nitrosative stress, producing anatomical and physiological cardiac alterations that can lead to heart failure. The present review aims to examine the molecular mechanisms involved in the bioavailability of NO and its modulation of downstream pathways. In particular, we focus on the main therapeutic targets and emphasize the recent evidence of preclinical and clinical studies, describing the different emerging therapeutic strategies developed to counteract NO impaired signalling and cardiovascular disease (CVD) development.

CTH G1208T and MTHFR A1298C polymorphisms are associated with a higher risk of a first myocardial infarction with fatal outcome among women

OBJECTIVES

Cystathionine-gamma-lyase (CSE) in the transsulfuration pathway generates hydrogen sulfide (H₂S), suggested regulating cardiovascular function. The G1208T polymorphism in the CTH gene, rs1021737, has, in addition to MTHFR, been found to increase homocysteine, related to myocardial infarction (MI) risk. This study aimed, for the first time, to investigate the associations of the polymorphisms CTH G1208T, MTHFR C677T, and A1298C with the prospective risk of developing a fatal or non-fatal first MI.

METHODS

This case-referent study included 545 cases later developing a first-ever MI and 1,054 referents from the Northern Sweden Health and Disease Study. Fatal MI was defined as death within 28 days after MI symptoms.

RESULTS

Women, but not men, had a positive association between fatal MI and the CTH G1208T, odds ratio [95% confidence interval] 3.14 [1.16-8.54] for heterozygotes, and the dominant model 3.22 [1.22-8.51], and for the MTHFR A1298C heterozygotes 3.24 [1.26-8.34] and the dominant model 2.63 [1.06-6.50]. The MTHFR C677T polymorphism was not related to MI.

CONCLUSIONS

This study indicates that the minor alleles of CTH G1208T and MTHFR A1298C polymorphisms are associated with a higher risk for a fatal MI among women but not for non-fatal MI. No association was found in men.

Pre-Treatment of Transplant Donors with Hydrogen Sulfide to Protect against Warm and Cold Ischemia-Reperfusion Injury in Kidney and Other Transplantable Solid Organs

Ischemia-reperfusion injury (IRI), a pathological condition resulting from prolonged cessation and subsequent restoration of blood flow to a tissue, is an inevitable consequence of solid organ transplantation. Current organ preservation strategies, such as static cold storage (SCS), are aimed at reducing IRI. However, prolonged SCS exacerbates IRI. Recent research has examined pre-treatment approaches to more effectively attenuate IRI. Hydrogen sulfide (H₂S), the third established member of a family of gaseous signaling molecules, has been shown to target the pathophysiology of IRI and thus appears to be a viable candidate that can overcome the transplant surgeon's enemy. This review discusses pre-treatment of renal grafts and other transplantable organs with H₂S to mitigate transplantation-induced IRI in animal models of transplantation. In addition, ethical principles of pre-treatment and potential applications of H₂S pre-treatment in the prevention of other IRI-associated conditions are discussed.

Prognostic impacts of Lipoxin A4 in patients with acute myocardial infarction: A prospective cohort study

Lipoxin A4 (LXA4) is one of the specialized pro-resolving lipid mediators proved to suppress the progression of atherosclerosis in vivo, but its clinical impacts in atherosclerotic patients is unclear. In this study, we assessed the prognostic impacts of LXA4 in patients with acute myocardial infarction (AMI). A total of 1569 consecutive AMI patients were prospectively recruited from March 2017 to January 2020. Plasma samples of AMI patients were collected, and LXA4 levels were determined using enzyme-linked immunosorbent assay. The primary outcome was major adverse cardiovascular event (MACE), a composite of all-cause death, recurrent MI, ischemic stroke, or ischemia-driven revascularization. Cox regression was used to assess associations between LXA4 and clinical outcomes. Overall, the median level of LXA4 was 5.637 (3.047-9.014) ng/mL for AMI patients. During a median follow-up of 786 (726-1108) days, high LXA4 (≥ 5.637 ng/mL) was associated with lower risk of MACE (hazard ratio [HR]: 0.73, 95% confidence interval [CI]: 0.60-0.89, P = 0.002), which was sustained in propensity score matching (HR: 0.73, 95% CI: 0.60-0.90, P = 0.004) and inverse probability weighting analysis (HR: 0.74, 95% CI: 0.61-0.90, P = 0.002). Combined with pro-inflammatory biomarker, patients with high levels of LXA4 (≥ 5.637 ng/mL) but low levels of high-sensitivity C-reactive protein (< 5.7 mg/L) acquired the lowest risk of MACE (HR: 0.68, 95% CI: 0.51-0.92, P = 0.012). In sum, high levels of LXA4 were associated with lower risk of recurrent ischemic events for AMI patients, which could serve as new therapeutic target to tackle cardiovascular inflammation.

Anserine and Carnosine Induce HSP70-Dependent H2S Formation in Endothelial Cells and Murine Kidney

Anserine and carnosine have nephroprotective actions; hydrogen sulfide (H₂S) protects from ischemic tissue damage, and the underlying mechanisms are debated. In view of their common interaction with HSP70, we studied possible interactions of both dipeptides with H₂S. H₂S formation was measured in human proximal tubular epithelial cells (HK-2); three endothelial cell lines (HUVEC, HUAEC, MCEC); and in renal murine tissue of wild-type (WT), carnosinase-1 knockout (Cndp1-KO) and Hsp70-KO mice. Diabetes was induced by streptozocin. Incubation with carnosine increased H₂S synthesis capacity in tubular cells, as well as with anserine in all three endothelial cell lines. H₂S dose-dependently reduced anserine/carnosine degradation rate by serum and recombinant carnosinase-1 (CN1). Endothelial Hsp70-KO reduced H₂S formation and abolished the stimulation by anserine and could be restored by Hsp70 transfection. In female Hsp70-KO mice, kidney H₂S formation was halved. In Cndp1-KO mice, kidney anserine concentrations were several-fold and sex-specifically increased. Kidney H₂S formation capacity was increased 2-3-fold in female mice and correlated with anserine and carnosine concentrations. In diabetic Cndp1-KO mice, renal anserine and carnosine concentrations as well as H₂S formation capacity were markedly reduced compared to non-diabetic Cndp1-KO littermates. Anserine and carnosine induce H₂S formation in a cell-type and Hsp70-specific manner within a positive feedback loop with CN1.

H2S in Critical Illness-A New Horizon for Sodium Thiosulfate?

Ever since the discovery of endogenous H2S and the identification of its cytoprotective properties, efforts have been made to develop strategies to use H2S as a therapeutic agent. The ability of H2S to regulate vascular tone, inflammation, oxidative stress, and apoptosis might be particularly useful in the therapeutic management of critical illness. However, neither the inhalation of gaseous H2S, nor the administration of inorganic H2S-releasing salts or slow-releasing H2S-donors are feasible for clinical use. Na2S2O3 is a clinically approved compound with a good safety profile and is able to release H2S, in particular under hypoxic conditions. Pre-clinical studies show promise for Na2S2O3 in the acute management of critical illness. A current clinical trial is investigating the therapeutic potential for Na2S2O3 in myocardial infarct. Pre-eclampsia and COVID-19 pneumonia might be relevant targets for future clinical trials.