Tristetraprolin, Inflammation, and Metabolic Syndrome in Arab Adults: A Case Control Study

Pb(II) coordination to the nonclassical zinc finger tristetraprolin: retained function with an altered fold

Tristetraprolin (TTP) is a nonclassical CCCH zinc finger (ZF) that plays a crucial role in regulating inflammation. TTP regulates cytokine mRNAs by specific binding of its two conserved ZF domains (CysX₈CysX₅CysX₃His) to adenylate-uridylate-rich sequences (AREs) at the 3'-untranslated region, leading to degradation of the RNA. Dysregulation of TTP in animal models has demonstrated several cytokine-related syndromes, including chronic inflammation and autoimmune disorders. Exposure to Pb(II), a prevalent environmental toxin, is known to contribute to similar pathologies, in part by disruption of and/or competition with cysteine-rich metalloproteins. TTP's role during stress as a ubiquitous translational regulator of cell signaling (and dysfunction), which may underpin various phenotypes of Pb(II) toxicity, highlights the importance of understanding the interaction between TTP and Pb(II). The impact of Pb(II) binding on TTP's fold and RNA-binding function was analyzed via UV-Vis spectroscopy, circular dichroism, X-ray absorption spectroscopy, nuclear magnetic resonance spectroscopy, and fluorescence anisotropy. A construct containing the two ZF domains of TTP (TTP-2D) bound to Pb(II) with nanomolar affinity and exhibited a different geometry and fold in comparison to Zn₂-TTP-2D. Despite the altered secondary structure, Pb(II)-substituted TTP-2D bound a canonical ARE sequence more selectively than Zn₂-TTP-2D. Taken together, these data suggest that Pb(II) may interfere with proper TTP regulation and hinder the cell's ability to respond to inflammation.

Correlation of White Blood Cell, Neutrophils, and Hemoglobin with Metabolic Syndrome and Its Components

Background

Metabolic syndrome (MetS) is a global health problem. White blood cell (WBC), neutrophils and neutrophil-to-lymphocyte ratio (NLR) are valid indicators involved in acute and chronic inflammation. The aims of our study were to analyze the correlation and severity of these indicators with MetS and its components, and explore the diagnostic value of their combined tests for MetS.

Methods

A total of 7726 subjects were recruited, and laboratory biomarkers were collected. The differences of indicators between MetS group and non-MetS group were analyzed. The linear trend between each indicator and the increasing number of metabolic disorders was analyzed using trend variance test. The correlation between each indicator and MetS with its components was analyzed by logistic regression.

Results

The levels of WBC, neutrophil, and hemoglobin grew significantly in the MetS group compared to non-MetS group, and gradually increased with the increased number of MetS disorders. Logistic regression analysis indicated significant correlations between WBC, neutrophils, and hemoglobin with MetS and its components. ROC curve analysis showed WBC, neutrophils, and hemoglobin served as good predictors for MetS, especially in adults aged under 40.

Conclusion

Our study indicated that WBC, neutrophils, and hemoglobin are efficient indicators for predicting MetS and evaluate its severity.

Diagnostic Value of Inflammatory Markers in Elderly Arab Women with Sarcopenia

Several studies have found a correlation between inflammatory markers and sarcopenia; however, limited research has been conducted on the Arabic population. Therefore, this study aimed to investigate the value of inflammatory parameters in Saudi elderly women with sarcopenia. In this cross-sectional study, 76 elderly Saudi women (>65 years) were stratified according to the presence (n = 26) or absence (n = 50) of sarcopenia, using the operational definition of the Asian Working Group for Sarcopenia (AWGS). Demographics and clinical data were collected. Muscle mass, muscle strength, and physical performance were assessed using bioelectrical impedance, hand grip and timed-up-and-go (TUG) tests, respectively. Inflammatory markers such as interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α) and C-reactive protein (CRP) were assessed using commercially available assays. Muscle mass and strength indicators were lower in the sarcopenia group (p-value < 0.05). Moreover, interleukin 6 (IL-6) was positively correlated with TUG (r = 0.48, p-value < 0.05), while CRP showed an inverse correlation with the right leg muscle (R-Leg-M) and a positive correlation with triceps skinfold (TSF) (r = −0.41, r = 0.42, respectively, p-values < 0.05). Additionally, TSF and R-Leg-M were independent predictors of CRP variation (R2 = 0.35; p < 0.01). Lastly, participants with a TNF-α > 71.2 were five times more likely to have sarcopenia [(OR = 5.85), 95% CI: 1.07−32.08; p = 0.04]. In conclusion, elevated levels of TNF-α are significantly associated with the risk of sarcopenia, while variations perceived in circulating CRP can be explained by changes in the muscle mass indices only among individuals with sarcopenia. The present findings, while promising, need further investigations on a larger scale to determine whether inflammatory markers hold any diagnostic value in assessing sarcopenia among elderly Arab women.

Angiogenin Levels and Their Association with Cardiometabolic Indices Following Vitamin D Status Correction in Saudi Adults

Simple Summary

Angiogenin (ANG) is a small 123 amino acid protein which in normal growth is associated with formation of new blood vessels in a process called angiogenesis; however, the abnormal levels of this protein in blood has been associated with diseases such as cancer, neurological disorders, and cardiovascular diseases. Vitamin D deficiency and elevated levels of blood lipids have also been associated with many diseases including cardiovascular diseases. In this study, the investigators tried to evaluate the relationship between the circulating levels of ANG, vitamin D, and lipids. The model used was vitamin D supplementation of deficient Saudi adults in order to find the effect of vitamin D correction on circulating levels of ANG and blood lipids. With vitamin D supplementation, modest but non-significant elevation in ANG was observed, as well as significant increase in apolipoproteins CIII and E and significant decrease in apo B. In addition, the correlation between circulating levels of ANG and apolipoproteins especially apo E observed in this study are interesting and should be investigated more as both are linked with neurologic disorders like Alzheimer’s and Parkinson’s diseases.

Abstract

Angiogenin (ANG), a multifunctional protein known to induce blood vessel formation, is a potential biomarker for cardiovascular diseases; however, whether it is affected by vitamin D supplementation is not known. This interventional study in vitamin D-deficient Saudi adults was designed to investigate it. A total of 100 vitamin D-deficient Saudi adults aged 30–50 years were randomly selected to undergo 6-month vitamin D supplementation. Circulating levels of fasting glucose, lipids, vitamin D, apolipoproteins (AI, AII, B, CI, CII, CIII, E, and H), and ANG were measured using commercially available assays at baseline and after six months. Overall, vitamin D levels increased significantly post intervention. With this, levels of apo-CIII and apo-E significantly increased (p-values of 0.001 and 0.009, respectively) with a significant parallel decrease in apo-B (p = 0.003). ANG levels were significantly positively associated with most apolipoproteins and inversely correlated with HDL-cholesterol. Post intervention, the changes in ANG levels were positively correlated with apo-E (r = 0.32; p < 0.01 in all subjects and r = 0.40; p < 0.05 in males). Vitamin D supplementation may modestly affect ANG levels. The association observed between ANG and apo-E is worthy of further investigation since both biomarkers have been linked to neurodegenerative disorders.