The atherogenic role of immune cells in familial hypercholesterolemia

Establishment and validation of a nomogram model containing a triglyceride-glucose index and neutrophil-to-high-density lipoprotein ratio for predicting major adverse cardiac events in patients with ST-segment elevation myocardial infarction

OBJECTIVE

To analyze the predictive value of the triglyceride-glucose (TyG) index and neutrophil-to-high-density lipoprotein ratio (NHR) for in-hospital major adverse cardiac events (MACE) after percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI), and to establish an associated nomogram model.

METHODS

In this retrospective study, we collected data from consecutive STEMI patients who underwent PCI from October 2019 to June 2023 at the Second People's Hospital of Hefei and the Second Affiliated Hospital of Anhui Medical University, as training and validation sets. Stepwise regression and multivariate logistic regression analysis were performed to screen independent risk factors, and a nomogram model was constructed and evaluated for its predictive efficacy.

RESULTS

The TyG index, NHR, urea, diastolic blood pressure, hypertension, and left ventricular ejection fraction were independent risk factors for in-hospital MACE after PCI, and were used to construct the nomogram model. The C-index of the training and validation sets were 0.799 and 0.753, respectively, suggesting that the model discriminated well. Calibration and clinical decision curves also demonstrated that the nomogram model had good predictive power.

CONCLUSION

In STEMI patients, increased TyG index and NHR were closely related to the occurrence of in-hospital MACE after PCI. Our constructed nomogram model has some value for predicting the occurrence of in-hospital MACE in STEMI patients.

Metabolism Serves as a Bridge Between Cardiomyocytes and Immune Cells in Cardiovascular Diseases

Metabolic disorders of cardiomyocytes play an important role in the progression of various cardiovascular diseases. Metabolic reprogramming can provide ATP to cardiomyocytes and protect them during diseases, but this transformation also leads to adverse consequences such as oxidative stress, mitochondrial dysfunction, and eventually aggravates myocardial injury. Moreover, abnormal accumulation of metabolites induced by metabolic reprogramming of cardiomyocytes alters the cardiac microenvironment and affects the metabolism of immune cells. Immunometabolism, as a research hotspot, is involved in regulating the phenotype and function of immune cells. After myocardial injury, both cardiac resident immune cells and heart-infiltrating immune cells significantly contribute to the inflammation, repair and remodeling of the heart. In addition, metabolites generated by the metabolic reprogramming of immune cells can further affect the microenvironment, thereby affecting the function of cardiomyocytes and other immune cells. Therefore, metabolic reprogramming and abnormal metabolite levels may serve as a bridge between cardiomyocytes and immune cells, leading to the development of cardiovascular diseases. Herein, we summarize the metabolic relationship between cardiomyocytes and immune cells in cardiovascular diseases, and the effect on cardiac injury, which could be therapeutic strategy for cardiovascular diseases, especially in drug research.

Maladaptive T-Cell Metabolic Fitness in Autoimmune Diseases

Immune surveillance and adaptive immune responses, involving continuously circulating and tissue-resident T-lymphocytes, provide host defense against infectious agents and possible malignant transformation while avoiding autoimmune tissue damage. Activation, migration, and deployment of T-cells to affected tissue sites are crucial for mounting an adaptive immune response. An effective adaptive immune defense depends on the ability of T-cells to dynamically reprogram their metabolic requirements in response to environmental cues. Inability of the T-cells to adapt to specific metabolic demands may skew cells to become either hyporesponsive (creating immunocompromised conditions) or hyperactive (causing autoimmune tissue destruction). Here, we review maladaptive T-cell metabolic fitness that can cause autoimmune diseases and discuss how T-cell metabolic programs can potentially be modulated to achieve therapeutic benefits.

Door to Balloon Time of Non-ST Elevation Myocardial Infarction May be Reconsidered According to Systemic Immune-Inflammation Index

Aim    Early diagnosis and treatment is very important in acute coronary syndromes (ACS). Previous studies showed that not all non-ST elevation myocardial infarction (NSTEMI) patients should be considered and treated in the same way. The systemic immune-inflammation index (SII), which is an easily accessible, rapidly computed, and cost-effective parameter, was evaluated in this study to determine the optimal intervention time for NSTEMI.Material and methods    469 patients diagnosed with ACS were included to the study. STEMI and NSTEMI patients were compared according to their SII. Univariate and binary logistic regression analysis were performed to determine which parameters have a significant effect on the discrimination of types of myocardial infarction.Results    The mean age of the patients was 61.43±11.52 yrs, and 348 (74.2 %) were male. NSTEMI patients with an SII value higher than 768×109 / l may be assumed to be STEMI (p<0.001). Univariate analysis and binary logistic regression showed that only SII and hypertension had statistically impact on differentiation of STEMI and NSTEMI. In addition, SII value of 1105×109 / l was the cut-off point for discrimination of cardiovascular survival (p<0.001, AUC =0.741). This study was performed to find out which NSTEMI patients should be treated percutaneously immediately after first medical contact according to SII. It was found that, SII value of higher than 768×109 / l is related with STEMI.Conclusion    In conclusion, NSTEMI patients with a SII value higher than 768×109 / l may be considered as STEMI and treated with in 120 min after first contact. In addition, SII was found to be a cardiovascular mortality predictor after myocardial infarction, and this may be used for identifying high-risk patients after percutaneous coronary intervention.

Increased extracellular vesicles (EVs) related to T cell-mediated inflammation and vascular function in familial hypercholesterolemia

Background and aims

OxLDL modulates innate and adaptive immunity, and extracellular vesicles (EVs) released from both non-immune and immune cells are proposed key players in atherosclerosis development. In the present study, we aimed to investigate EVs expressing markers related to adaptive immunity-driven inflammation and endothelial activation/dysfunction in hypercholesterolemic patients.

Methods

EVs were phenotyped in thirty patients with familial hypercholesterolemia (FH) and twenty-three healthy controls using the Extracellular Vesicle (EV) Array with antibodies targeting proteins expressed on B and T cells, and endothelial cells.

Results

FH patients had a higher atherosclerotic burden, as determined by the mean carotid intima-media thickness (IMT) (0.64 ± 0.12 mm vs. 0.58 ± 0.07 mm; p = 0.033), higher oxLDL levels (p < 0.0001), and showed increased levels of EV-specific markers: CD9 (p = 0.017), CD63 (p = 0.045), CD81 (p = 0.003), Annexin V (p = 0.018), and EV markers related to adaptive/lymphocyte immunity: CD28 (p = 0.034), CD4 (p = 0.049), CD152 (p = 0.029), LFA-1 (p = 0.024), and endothelial function: CD62E (p = 0.032), CD144 (p = 0.018), tPA (p = 0.017), CD31 (p = 0.024). Linear regression revealed a positive relationship between carotid IMT and several of the increased markers observed within the FH group, including CD9 (β = 0.33; p = 0.022), CD63 (β = 0.35; p 225 = 0.026), CD28 (β = 0.37; p = 0.026), CD4 (β = 0.40; p = 0.025), CD152 (β = 0.41; p = 0.017), LFA-1 (β = 0.42; p = 0.014) and CD62E (β = 0.38; p = 0.024).

Conclusion

EVs associated with adaptive immunity and endothelial dysfunction are elevated in FH patients, and several markers related to a higher atherosclerotic burden.

Long-term Prognosis after Treatment of Total Occluded Coronary Artery is well Predicted by Neutrophil to High-Density Lipoprotein Ratio: a Comparison Study

Aim    Mortality prediction is very important for more effective treatment of patients with acute coronary syndrome. Hematological and lipid parameters have been used for this purpose, as this approach is non-invasive and cost effective. In this study, our aim was to evaluate which parameter predicts mortality most accurately.Material and Methods    Data of 554 patients with at least one total coronary artery occlusion were collected retrospectively. Receiver operating characteristic curves were used to determine the optimal cut-off points of Neu / HDL, Neu / Lym, Mono / HDL, Trig / HDL, HDL / LDL, Plt / Lym and Lym / HDL according to long-term cardiovascular survival. Median follow-up time was 520 days, and 30 patients died.Results    The mean age was 60.96±0.50 yrs. The area under the curve (AUC) for Neu / HDL was 0.830 (p&lt;0.001, 95 % confidence interval [CI]: 0.753 to 0.908). The cut-off point was 0.269, with a sensitivity of 74.2 % and a specificity of 74.2 %. The AUC for Neu / Lym was 0.688 (p&lt;0.001, 95 % CI: 0.586 to 0.790). The cut-off point was 5.322, with a sensitivity of 67.7 % and a specificity of 67.1 %. The Neu / HDL (hazard ratio, HR [confidence interval, CI]: 0.202 [0.075-0.545], p=0.002) and Neu / Lym (0.306 [0.120-0.777], p=0.013) were associated with increased risk of death according to multivariate Cox regression analysis.Conclusions    Neu / HDL offers a better long-term mortality prediction than Neu / Lym, Mono / HDL, Trig / HDL, HDL / LDL, Plt / Lym, or Lym / HDL after treatment of total coronary artery occlusion.

Mice lacking global Stap1 expression do not manifest hypercholesterolemia

Background

Autosomal dominant familial hypercholesterolemia (ADH; MIM#143890) is one of the most common monogenic disorders characterized by elevated circulatory LDL cholesterol. Initial studies in humans with ADH identified a potential relationship with variants of the gene encoding signal transducing adaptor family member protein 1 (STAP1; MIM#604298). However, subsequent studies have been contradictory. In this study, mice lacking global Stap1 expression (Stap1^−/−) were characterized under standard chow and a 42% kcal western diet (WD).

Methods

Mice were studied for changes in different metabolic parameters before and after a 16-week WD regime. Growth curves, body fats, circulatory lipids, parameters of glucose homeostasis, and liver architecture were studied for comparisons.

Results

Surprisingly, Stap1^−/− mice fed the 16-week WD demonstrated no marked differences in any of the metabolic parameters compared to Stap1^+/+ mice. Furthermore, hepatic architecture and cholesterol content in FPLC-isolated lipoprotein fractions also remained comparable to wild-type mice.

Conclusion

These results strongly suggest that STAP1 does not alter lipid levels, that a western diet did not exacerbate a lipid disorder in Stap1 deficient mice and support the contention that it is not causative for hyperlipidemia in ADH patients. These results support other published studies also questioning the role of this locus in human hypercholesterolemia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12881-020-01176-x.

Immunogenetics of Atherosclerosis-Link between Lipids, Immunity, and Genes

PURPOSE OF REVIEW

Atherosclerosis is a complex disease process with lipid as a traditional modifiable risk factor and therapeutic target in treating atherosclerotic cardiovascular disease (ACVD). Recent evidence indicates that genetic influence and host immune response also are vital in this process. How these elements interact and modify each other and if immune response may emerge as a novel modifiable target remain poorly understood.

RECENT FINDINGS

Numerous preclinical studies have clearly demonstrated that hypercholesterolemia is essential for atherogenesis, but genetic variations and host immune-inflammatory responses can modulate the pro-atherogenic effect of elevated LDL-C. Clinical studies also suggest that a similar paradigm may also be operational in atherogenesis in humans. More importantly each element modifies the biological behavior of the other two elements, forming a triangular relationship among the three. Modulating any one of them will have downstream impact on atherosclerosis. This brief review summarizes the relationship among lipids, genes, and immunity in atherogenesis and presents evidence to show how these elements affect each other. Modulation of immune response, though in its infancy, has a potential to emerge as a novel clinical strategy in treating ACVD.