Uric acid, as a double-edged sword, affects the activity of epidermal growth factor (EGF) on human umbilical vein endothelial cells by regulating aging process

Relationships between systemic sclerosis and atherosclerosis: screening for mitochondria-related biomarkers

Background

Patients with systemic sclerosis (SSc) are known to have higher incidence of atherosclerosis (AS). Mitochondrial injuries in SSc can cause endothelial dysfunction, leading to AS; thus, mitochondria appear to be hubs linking SSc to AS. This study aimed to identify the mitochondria-related biomarkers of SSc and AS.

Methods

We identified common differentially expressed genes (DEGs) in the SSc (GSE58095) and AS (GSE100927) datasets of the Gene Expression Omnibus (GEO) database. Considering the intersection between genes with identical expression trends and mitochondrial genes, we used the least absolute shrinkage and selection operator (LASSO) as well as random forest (RF) algorithms to identify four mitochondria-related hub genes. Diagnostic nomograms were then constructed to predict the likelihood of SSc and AS. Next, we used the CIBERSORT algorithm to evaluate immune infiltration in both disorders, predicted the transcription factors for the hub genes, and validated these genes for the two datasets.

Results

A total of 112 genes and 13 mitochondria-related genes were identified; these genes were then significantly enriched for macrophage differentiation, collagen-containing extracellular matrix, collagen binding, antigen processing and presentation, leukocyte transendothelial migration, and apoptosis. Four mitochondria-related hub DEGs (IFI6, FSCN1, GAL, and SGCA) were also identified. The nomograms showed good diagnostic values for GSE58095 (area under the curve (AUC) = 0.903) and GSE100927 (AUC = 0.904). Further, memory B cells, γδT cells, M0 macrophages, and activated mast cells were significantly higher in AS, while the resting memory CD4+ T cells were lower and M1 macrophages were higher in SSc; all of these were closely linked to multiple immune cells. Gene set enrichment analysis (GSEA) showed that IFI6 and FSCN1 were involved in immune-related pathways in both AS and SSc; GAL and SGCA are related to mitochondrial metabolism pathways in both SSc and AS. Twenty transcription factors (TFs) were predicted, where two TFs, namely BRCA1 and PPARγ, were highly expressed in both SSc and AS.

Conclusion

Four mitochondria-related biomarkers were identified in both SSc and AS, which have high diagnostic value and are associated with immune cell infiltration in both disorders. Hence, this study provides new insights into the pathological mechanisms underlying SSc and AS. The specific roles and action mechanisms of these genes require further clinical validation in SSc patients with AS.

Recent advances in hematopoietic cell kinase in cancer progression: Mechanisms and inhibitors

Hematopoietic cell kinase (Hck), a non-receptor tyrosine kinase belonging to the Src kinase family, is intricately linked to the pathogenesis of numerous human diseases, with a particularly pronounced association with cancer. Hck not only directly impacts the proliferation, migration, and apoptosis of cancer cells but also interacts with JAK/STAT, MEK/ERK, PI3K/AKT, CXCL12/CXCR4, and other pathways. Hck also influences the tumor microenvironment to facilitate the onset and progression of cancer. This paper delves into the functional role and regulatory mechanisms of Hck in various solid tumors. Additionally, it explores the implications of Hck in hematological malignancies. The review culminates with a summary of the current research status of Hck inhibitors, the majority of which are in the pre-clinical phase of investigation. Notably, these inhibitors are predominantly utilized in the therapeutic management of leukemia, with their combinatorial potential indicating promising avenues for future research. In conclusion, this review underscores the significance of the mechanism of Hck in solid tumors. This insight is crucial for comprehending the current research trends regarding Hck: targeted therapy against Hck shows great promise in both diagnosis and treatment of malignant tumors. Further investigation into the role of Hck in cancer, coupled with the development of specific inhibitors, has the potential to revolutionize approaches to cancer treatment.

Potential protective effects of increased serum uric acid concentration in sarcopenia: A meta-analysis and systematic review

BACKGROUND

Previous studies on the association between serum uric acid (UA) levels and sarcopenia have yielded contradictory results. This meta-analysis and literature review assessed the association between serum UA levels and sarcopenia. Moreover, we conducted a comparative analysis of the differences in serum UA concentrations between individuals with and without sarcopenia.

METHODS

A systematic search was conducted across various medical databases, namely PubMed, EMBASE, Web of Science, Cochrane Library, CNKI, and Wanfang (from the start to August 20, 2023). This search focused on published studies that investigated the relationship between serum UA levels and sarcopenia. The relationship between serum UA concentration and the occurrence of sarcopenia was analyzed, and the differences in serum UA concentrations between individuals with sarcopenia and control groups were reviewed. Statistical analysis was performed using STATA 11.0 and R 4.1.3.

RESULTS

Sixteen studies were considered for our analysis. The results indicated a significant association between low serum UA concentration and a higher sarcopenia risk, particularly among male patients (adjusted odds ratio = 0.65, 95% confidence interval [CI] = 0.49, 0.87, P = .004, I2 = 0%). Individuals with sarcopenia exhibited decreased serum UA concentrations compared with those of the control group (mmol/L: weighted mean difference = -28.25, 95% CI = -40.45, -16.05, P < .001; mg/dL: weighted mean difference = -0.82, 95% CI = -1.05, -0.58, P < .001). Additionally, serum UA concentration was positively correlated with skeletal muscle mass index and handgrip strength (skeletal muscle index: correlation coefficient = 0.17, 95% CI = 0.11, 0.22, P < .001; handgrip strength: common odds ratios = 0.10, 95% CI = 0.06, 0.14, P < .001).

CONCLUSION

Individuals with sarcopenia have relatively low serum UA concentrations. A notable correlation between serum UA concentration and sarcopenia was observed. Hence, monitoring UA levels could aid in the early detection and treatment of sarcopenia, enabling timely intervention to preserve muscle mass and strength.

Leukocyte telomere length independently predicts hyperuricemia risk in a longitudinal study of the Chinese population

BACKGROUND AND AIMS

Leukocyte telomere length (LTL) has been correlated with uric acid levels, although results are inconsistent, and prospective studies are lacking. In this longitudinal, prospective cohort study, we aimed to assess whether a shorter LTL predicts the risk of hyperuricemia.

METHODS AND RESULTS

We conducted a longitudinal study in a Chinese cohort of 599 participants. Of these, 266 participants completed a 5.9-year follow-up from June 2014 to December 2021. LTL was assessed at baseline using real-time polymerase chain reaction. Hyperuricemia was defined as serum uric acid ≥420 mmol/L according to Chinese guidelines for diagnosis and treatment of hyperuricemia and gout. Participants who had developed hyperuricemia during follow-up (n = 17) had shorter LTL at baseline. Baseline LTL was independently associated with the development of hyperuricemia at follow-up after adjusting for conventional hyperuricemia risk factors (odds ratio [OR] 2.347 [95% confidence interval [CI] 1.123, 4.906]; P = 0.023). After grouping according to LTL tertiles, the incidence of hyperuricemia was 18.334-fold higher for the first than for the third tertile (OR 18.334 [95%CI 1.786, 191.272]; P = 0.014, P for trend = 0.050).

CONCLUSION

Our findings in a prospective cohort suggest that LTL could predict hyperuricemia risk, which might inform the timely prevention and treatment of hyperuricemia.

New Dawn for Atherosclerosis: Vascular Endothelial Cell Senescence and Death

Endothelial cells (ECs) form the inner linings of blood vessels, and are directly exposed to endogenous hazard signals and metabolites in the circulatory system. The senescence and death of ECs are not only adverse outcomes, but also causal contributors to endothelial dysfunction, an early risk marker of atherosclerosis. The pathophysiological process of EC senescence involves both structural and functional changes and has been linked to various factors, including oxidative stress, dysregulated cell cycle, hyperuricemia, vascular inflammation, and aberrant metabolite sensing and signaling. Multiple forms of EC death have been documented in atherosclerosis, including autophagic cell death, apoptosis, pyroptosis, NETosis, necroptosis, and ferroptosis. Despite this, the molecular mechanisms underlying EC senescence or death in atherogenesis are not fully understood. To provide a comprehensive update on the subject, this review examines the historic and latest findings on the molecular mechanisms and functional alterations associated with EC senescence and death in different stages of atherosclerosis.

High-normal serum uric acid predicts macrovascular events in patients with type 2 diabetes mellitus without hyperuricemia based on a 10-year cohort

BACKGROUND AND AIMS

The upper limits of normal serum uric acid (SUA) or the lower limits of hyperuricemia were frequently set at 420 or 360 μmol/L (7.0 or 6.0 mg/dL). We aimed to explore the association between high-normal SUA (360 ≤ SUA≤420 μmol/L) and incidence of macrovascular and renal events based on a 10-year cohort with type 2 diabetes mellitus (T2DM) to explore which cut-off was more appropriate.

METHODS AND RESULTS

A total of 2988 patients with T2DM without hyperuricemia (SUA≤420 μmol/L) were included and followed up. Cox proportional hazards models and restricted cubic spline regression were used to evaluate the relationship between baseline SUA (as continuous and categorical variable) and macrovascular and renal events. Patients were grouped as low-normal (SUA<360 μmol/L) and high-normal groups based on baseline SUA, and the latter group had higher incidence of macrovascular events. Multivariate Cox regression analysis indicated that baseline levels of SUA were significantly associated with cardiovascular (HR = 1.385, 95%CI:1.190-1.613, P < 0.001) and peripheral vascular events (HR = 1.266, 95%CI:1.018-1.574, P = 0.034), and the linear association existed. Moreover, fully adjusted multivariable Cox analyses indicated high-normal SUA increased the risks of cardiovascular (HR = 1.835, 95%CI:1.319-2.554, P < 0.001) and peripheral vascular events (HR = 1.661, 95%CI:1.000-2.760, P = 0.050) compared to low-normal SUA.

CONCLUSIONS

Baseline SUA levels were positively associated with cardiovascular and peripheral vascular events, and high-normal SUA increased the risks of these events in patients with T2DM even without hyperuricemia. A threshold value for SUA of 360 μmol/L should be more appropriate in terms of predicting macrovascular events risks compared to the value of 420 μmol/L.

Uric Acid Reacts with Peroxidasin, Decreases Collagen IV Crosslink, Impairs Human Endothelial Cell Migration and Adhesion

Uric acid is considered the main substrate for peroxidases in plasma. The oxidation of uric acid by human peroxidases generates urate free radical and urate hydroperoxide, which might affect endothelial function and explain, at least in part, the harmful effects of uric acid on the vascular system. Peroxidasin (PXDN), the most recent heme-peroxidase described in humans, catalyzes the formation of hypobromous acid, which mediates collagen IV crosslinks in the extracellular matrix. This enzyme has gained increasing scientific interest since it is associated with cardiovascular disease, cancer, and renal fibrosis. The main objective here was to investigate whether uric acid would react with PXDN and compromise the function of the enzyme in human endothelial cells. Urate decreased Amplex Red oxidation and brominating activity in the extracellular matrix (ECM) from HEK293/PXDN overexpressing cells and in the secretome of HUVECs. Parallelly, urate was oxidized to 5-hydroxyisourate. It also decreased collagen IV crosslink in isolated ECM from PFHR9 cells. Urate, the PXDN inhibitor phloroglucinol, and the PXDN knockdown impaired migration and adhesion of HUVECs. These results demonstrated that uric acid can affect extracellular matrix formation by competing for PXDN. The oxidation of uric acid by PXDN is likely a relevant mechanism in the endothelial dysfunction related to this metabolite.