Lipoprotein(a) Gene Polymorphism Increases a Risk Factor for Aortic Valve Calcification

Methylation status, mRNA and protein expression of the SMAD4 gene in patients with non-melanocytic skin cancers

BACKGROUND

SMAD4 is a potent tumor suppressor. SMAD4 loss increases genomic instability and plays a critical role in the DNA damage response that leads to skin cancer development. We aimed to investigate SMAD4 methylation effects on mRNA and protein expression of SMAD4 in cancer and healthy tissues from patients with basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and basosquamous skin cancer (BSC).

METHODS AND RESULTS

The study included 17 BCC, 24 cSCC and nine BSC patients. DNA and RNA were isolated from cancerous and healthy tissues following punch biopsy. Methylation-specific polymerase chain reaction (PCR) and real-time quantitative PCR methods were used to examine SMAD4 promoter methylation and SMAD4 mRNA levels, respectively. The percentage and intensity of staining of the SMAD4 protein were determined by immunohistochemistry. The percentage of SMAD4 methylation was increased in the patients with BCC (p = 0.007), cSCC (p = 0.004), and BSC (p = 0.018) compared to the healthy tissue. SMAD4 mRNA expression was decreased in the patients with BCC (p˂0.001), cSCC (p˂0.001), and BSC (p = 0.008). The staining characteristic of SMAD4 protein was negative in the cancer tissues of the patients with cSCC (p = 0.00). Lower SMAD4 mRNA levels were observed in the poorly differentiated cSCC patients (p = 0.001). The staining characteristics of the SMAD4 protein were related to age and chronic sun exposure.

CONCLUSIONS

Hypermethylation of SMAD4 and reduced SMAD4 mRNA expression were found to play a role in the pathogenesis of BCC, cSCC, and BSC. A decrease in SMAD4 protein expression level was observed only in cSCC patients. This suggests that epigenetic alterations to the SMAD4 gene are associated with cSCC.

TRIAL REGISTRATION

The name of the trial register: SMAD4 Methylation and Expression Levels in Non-melanocytic Skin Cancers; SMAD4 Protein Positivity. The registration number: NCT04759261 ( https://clinicaltrials.gov/ct2/results?term=NCT04759261 ).

Epidemiological study of calcified aortic valve stenosis in a Chinese community population

BACKGROUND AND AIMS

Due to the ageing global population, calcified aortic valve disease is currently the most common cardiac valve disorder. This study aimed to investigate the prevalence and the risk factors for calcified aortic valve stenosis (CAVS), and develop a prediction model for predicting CAVS risk.

METHODS AND RESULTS

This study was derived from the cross-sectional baseline survey of the PRECISE study (NCT03178448). The demographic, clinical and laboratory information of each participant was obtained. Univariable and multivariable logistic regression models were used to determine CAVS risk factors. A prediction model for predicting CAVS risk based on risk factors was developed and the result was performed by nomogram. The discrimination of the prediction model was assessed by receiver operating characteristic curve analysis. The degree of fitting for the prediction model was assessed by calibration curve analysis. A total of 3067 participants (1427 men and 1640 women) were included. The prevalence of CAVS among those aged below 60 years old, 60-70 years old and over 70 years old was 4.1%, 10.3% and 21.9%, respectively. Multivariable regression analysis revealed that age (OR: 1.099; 95% CI: 1.076 to 1.123, p<0.001), pulse pressure (OR: 1.020; 95% CI: 1.009 to 1.031, p<0.001), uric acid (OR: 1.003; 95% CI: 1.001 to 1.004, p<0.001), glycosylated haemoglobin (HbA1c) (OR: 1.152; 95% CI: 1.028 to 1.292, p=0.015) and lipoprotein(a) (OR: 1.002; 95% CI: 1.001 to 1.002, p<0.001) were independent risk factors for CAVS. High-density lipoprotein cholesterol (HDL-C) was a protective factor for CAVS (OR: 0.539; 95% CI: 0.349 to 0.831, p=0.005). The prediction model including the above risk factors showed a risk prediction of CAVS with good discrimination. The area under the curve value was found to be 0.743 (95% CI: 0.711 to 0.775).

CONCLUSION

CAVS is currently prevalent in the elderly Chinese population. Age, pulse pressure, HbA1c, lower-level HDL-C, lipoprotein(a) and uric acid are the independent risk factors for CAVS.

Lipoprotein(a) and calcific aortic valve disease initiation and progression: a systematic review and meta-analysis

Although evidence indicates the association of lipoprotein(a) [Lp(a)] with atherosclerosis, the link with calcific aortic valve disease (CAVD) is unclear. This systematic review and meta-analysis explores the connection between Lp(a) and aortic valve calcification and stenosis (AVS). We included all relevant studies, indexed in eight databases, up to February 2023. A total of 44 studies (163 139 subjects) were included, with 16 of them being further meta-analysed. Despite considerable heterogeneity, most studies support the relationship between Lp(a) and CAVD, especially in younger populations, with evidence of early aortic valve micro-calcification in elevated-Lp(a) populations. The quantitative synthesis showed higher Lp(a) levels, by 22.63 nmol/L (95% CI: 9.98-35.27), for patients with AVS, while meta-regressing the data revealed smaller Lp(a) differences for older populations with a higher proportion of females. The meta-analysis of eight studies providing genetic data, revealed that the minor alleles of both rs10455872 and rs3798220 LPA gene loci were associated with higher risk for AVS (pooled odds ratio 1.42; 95% CI: 1.34-1.50 and 1.27; 95% CI: 1.09-1.48, respectively). Importantly, high-Lp(a) individuals displayed not only faster AVS progression, by a mean difference of 0.09 m/s/year (95% CI: 0.09-0.09), but also a higher risk of serious adverse outcomes, including death (pooled hazard ratio 1.39; 95% CI: 1.01-1.90). These summary findings highlight the effect of Lp(a) on CAVD initiation, progression and outcomes, and support the early onset of Lp(a)-related subclinical lesions before clinical evidence.

Association of aortic valve calcification and high levels of lipoprotein (a): Systematic review and Meta-analysis

AIM

This study aimed to assess the association between aortic valve calcification and lipoprotein (a).

METHODS

We searched PUBMED, WOS, and SCOPUS databases. Inclusion criteria were any controlled clinical trials or observational studies that reported the level of Lipoprotein A in patients with aortic valve calcifications, excluding case reports, editorials and animal studies. RevMan software (5.4) was used to perform the meta-analysis.

RESULTS

After complete screening, 7 studies were included with a total number of 446179 patients included in the analysis. The pooled analysis showed a statistically significant association between the incidence of aortic valve calcium and increased levels of lipoprotein (a) compared with controls (SMD = 1.71, 95% CI = 1.04 to 2.38, p-value < 0.00001).

CONCLUSION

This meta-analysis showed a statistically significant association between the incidence of aortic valve calcium and increased levels of lipoprotein (a) compared with controls. Patients with high levels of lipoprotein (a) are at increased risk of developing aortic valve calcification. Medications targeting lipoprotein (a) in future clinical trials may be useful in primary prevention of aortic valve calcification in high risk patients.

Exploration and validation of the influence of angiogenesis-related factors in aortic valve calcification

Over the years, bioinformatics tools have been used to identify functional genes. In the present study, bioinformatics analyses were conducted to explore the underlying molecular mechanisms of angiogenic factors in calcific aortic valve disease (CAVD). The raw gene expression profiles were from datasets GSE153555, GSE83453, and GSE51472, and the angiogenesis-related gene set was from the Gene Set Enrichment Analysis database (GSEA). In this study, R was used to screen for differentially expressed genes (DEGs) and co-expressed genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genome (KEGG) Pathway enrichment analysis were performed on DEGs and validated in clinical samples. DEGs in CAVD were significantly enriched in numerous immune response pathways, inflammatory response pathways and angiogenesis-related pathways. Nine highly expressed angiogenesis-related genes were identified, of which secretogranin II (SCG2) was the most critical gene. MiRNA and transcription factors (TFs) networks were established centered on five DEGs, and zinc finger E-box binding homeobox 1 (ZEB1) was the most important transcription factor, verified by PCR, immunohistochemical staining and western blotting experiments. Overall, this study identified key genes and TFs that may be involved in the pathogenesis of CAVD and may have promising applications in the treatment of CAVD.

Lipoprotein(a), a Lethal Player in Calcific Aortic Valve Disease

Calcified aortic valve disease (CAVD) is the most common valvular cardiovascular disease with increasing incidence and mortality. The primary treatment for CAVD is surgical or transcatheter aortic valve replacement and there remains a lack of effective drug treatment. Recently, lipoprotein (a) (Lp(a)) has been considered to play a crucial role in CAVD pathophysiology. Multiple studies have shown that Lp(a) represents an independent risk factor for CAVD. Moreover, Lp(a) mediates the occurrence and development of CAVD by affecting aortic valve endothelial dysfunction, indirectly promoting foam cell formation through oxidized phospholipids (OxPL), inflammation, oxidative stress, and directly promotes valve calcification. However, there is a lack of clinical trials with Lp(a) reduction as a primary endpoint. This review aims to explore the relationship and mechanism between Lp(a) and CAVD, and focuses on the current drugs that can be used as potential therapeutic targets for CAVD.

Lipoprotein(a)—The Crossroads of Atherosclerosis, Atherothrombosis and Inflammation

Increased lipoprotein(a) (Lp(a)) levels are an independent predictor of coronary artery disease (CAD), degenerative aortic stenosis (DAS), and heart failure independent of CAD and DAS. Lp(a) levels are genetically determinated in an autosomal dominant mode, with great intra- and inter-ethnic diversity. Most variations in Lp(a) levels arise from genetic variations of the gene that encodes the apolipoprotein(a) component of Lp(a), the LPA gene. LPA is located on the long arm of chromosome 6, within region 6q2.6–2.7. Lp(a) levels increase cardiovascular risk through several unrelated mechanisms. Lp(a) quantitatively carries all of the atherogenic risk of low-density lipoprotein cholesterol, although it is even more prone to oxidation and penetration through endothelia to promote the production of foam cells. The thrombogenic properties of Lp(a) result from the homology between apolipoprotein(a) and plasminogen, which compete for the same binding sites on endothelial cells to inhibit fibrinolysis and promote intravascular thrombosis. LPA has up to 70% homology with the human plasminogen gene. Oxidized phospholipids promote differentiation of pro-inflammatory macrophages that secrete pro-inflammatory cytokines (e. g., interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor-α). The aim of this review is to define which of these mechanisms of Lp(a) is predominant in different groups of patients.

Racial disparities in the treatment of aortic stenosis: Has transcatheter aortic valve replacement bridged the gap?

BACKGROUND

Racial disparities in outcomes and utilization of surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis (AS) is well known. While transcatheter aortic valve replacement (TAVR) has become more widespread, its impact on racial disparities remains unclear.

OBJECTIVES

Our goal was to assess the utilization of SAVR and TAVR and their clinical outcomes among various racial groups.

METHODS

The National Inpatient database (2009-2015) was used to study the racial distribution of admissions for SAVR and TAVR, and their impact on inpatient outcomes. Survey estimation commands were used to determine weighted national estimates.

RESULTS

There were 3,445,267; 294,108; and 52,913 inpatient visits for AS, SAVR, and TAVR, respectively. SAVR visits were 86% White, 3.8% Black, 5.5% Hispanic, 1.2% Asian/Pacific Islander (A/PI), 0.4% Native American (NA), and 2.9%; TAVR were 87.7% White, 3.7% Black, 3.8% Hispanic, 1.0% A/PI, 0.2% NA, and 3.5% Other while AS visits were 83.7% White, 6.7% Black, 5.3% Hispanic, 1.7% A/PI, 0.4% NA, and 2.2% Other. Racial minorities generally had more co-morbidities compared with Whites. After SAVR, Black patients had a higher unadjusted inpatient mortality than Whites, however, there was no difference after adjustment for other variables. A/PI were more likely to require a permanent pacemaker after SAVR. Need for blood transfusion was significantly higher among the minorities compared with Whites, except for NA, but there were no racial differences in stroke rates. There was no difference in inpatient mortality, pacemaker implantation, stroke, and bleeding after TAVR, but acute kidney injury occurred more often in Hispanics, A/PI, and "others" compared with Whites.

CONCLUSIONS

Racial disparities in the treatment of AS continues in the contemporary era; however it was found that TAVR resulted in comparable inpatient outcomes, despite higher comorbidities, and adverse socioeconomic factors in minorities.

Current Evidence and Future Perspectives on Pharmacological Treatment of Calcific Aortic Valve Stenosis

Calcific aortic valve stenosis (CAVS), the most common heart valve disease, is characterized by the slow progressive fibro-calcific remodeling of the valve leaflets, leading to progressive obstruction to the blood flow. CAVS is an increasing health care burden and the development of an effective medical treatment is a major medical need. To date, no effective pharmacological therapies have proven to halt or delay its progression to the severe symptomatic stage and aortic valve replacement represents the only available option to improve clinical outcomes and to increase survival. In the present report, the current knowledge and latest advances in the medical management of patients with CAVS are summarized, placing emphasis on lipid-lowering agents, vasoactive drugs, and anti-calcific treatments. In addition, novel potential therapeutic targets recently identified and currently under investigation are reported.