Blood levels of heme oxygenase-1 versus bilirubin in patients with coronary artery disease

Anti-Inflammatory Activity of 1,6,7-Trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone Isolated from Cudrania tricuspidata via NF-κB, MAPK, and HO-1 Signaling Pathways in Lipopolysaccharide-Stimulated RAW 264.7 and BV2 Cells

Neuroinflammation activated by microglia affects inflammatory pain development. This study aimed to explore the anti-inflammatory properties and mechanisms of 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3-methoxyxanthone (THMX) from Cudrania tricuspidata in microglia activation-mediated inflammatory pain. In RAW 264.7 and BV2 cells, THMX has been shown to reduce lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory mediators and cytokines, including nitric oxide (NO), prostaglandin (PG) E2, interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α). THMX also decreased LPS-induced phosphorylation of mitogen-activated protein kinase (MAPK) and the activation of p65 nuclear factor kappa B (NF-κB). Interestingly, THMX also activated heme oxygenase (HO)-1 expression. These findings suggest that THMX is a promising biologically active compound against inflammation through preventing MAPKs and NF-ĸB and activating HO-1 signaling pathways.

Serum Bilirubin Associated with Stroke Severity and Prognosis: Preliminary Findings on Liver Function after Acute Ischemic Stroke

OBJECTIVE

This study investigates relationships between serum bilirubin, stroke severity, and prognosis of patients with acute ischemic stroke (AIS) to elucidate the roles of the liver in AIS.

METHODS

This retrospective study collected data from 527 patients diagnosed with AIS within 24 hours after their symptom onset. Stroke severity was assessed using the National Institutes of Health Stroke Scale (NIHSS). Mild stroke was defined as NIHSS≤5. Prognosis was assessed with modified Rankin Scale (mRS) on 90 days after AIS and good prognosis was defined as mRS≤2. The patients were divided based on their total bilirubin (Tbil) and direct bilirubin (Dbil) levels to study these serum markers' association with the severity of stroke. Tbil levels were measured and compared with mRS on 90 days to analyze prognosis of mild stroke patients.

RESULTS

Both Tbil abnormal (NIHSS = 6.8 ± 5.3) and Dbil abnormal groups (NIHSS = 7.3 ± 5.7) had higher NIHSS scores on admission than the normal groups (p< 0.05 or p< 0.01, respectively). Severity of stroke at discharge was similar between these groups (p = 0.025 and 0.019, respectively). Serum bilirubin levels were independently associated with stroke severity on admission and discharge after risk factors were adjusted (p< 0.001 and p< 0.05, respectively; β (95%CI) were 0.116 (0.064-0.167) and 0.058 (0.012-0.103), respectively). The average Tbil levels of mild stroke with good prognosis was 15.1 ± 6.4umol/l versus 11.8 ± 3.1umol/l with poor prognosis; this difference was statistically significant (p = 0.003). The same difference was observed with Dtil levels but it did not reach a significant level.

CONCLUSION

High Tbil and Dbil level within 48 hours of symptom onset could be an independent marker of severity of stroke on admission and discharge for all AIS patients. For patient with mild stroke, elevation of bilirubin after AIS suggests a good prognosis. These findings imply that the liver play the key roles in the mechanism of AIS.

Serum Bilirubin Levels and Disease Severity in Patients with Pneumoconiosis

Aim

To investigate the association between serum bilirubin and disease severity in patients with pneumoconiosis.

Methods

The study comprised 45 patients with pneumoconiosis retrospectively; all pneumoconiosis patients were classified into I, II, and III stage according to the radiological severity.

Results

Serum direct bilirubin levels were significantly lower in III stage pneumoconiosis patients than those in I/II stage (p = 0.012) but not serum indirect bilirubin. Serum direct bilirubin was negatively correlated with radiological severity in patients with pneumoconiosis (r = -0.320; p = 0.032); by multiple linear-regression analysis, we observed that serum direct bilirubin levels had independent association with radiological severity in patients with pneumoconiosis (beta = -0.459; p = 0.005).

Conclusions

Serum direct bilirubin levels are negatively associated with disease severity in patients with pneumoconiosis.

Role of bilirubin in the prognosis of coronary artery disease and its relationship with cardiovascular risk factors: a meta-analysis

Background

Bilirubin is a heme catabolism product with antioxidant, anti-inflammatory, and anti-apoptotic properties and is implicated in the prognosis of several diseases. This study evaluates the prognostic role of bilirubin in coronary artery disease (CAD) patients.

Methods

After identifying studies from the literature, meta-analyses were performed to achieve a) overall estimates of serum total bilirubin levels in patients with myocardial infarction (MI), non-MI CAD and healthy individuals; b) odds ratios (OR) of adverse outcomes between higher and lower total bilirubin levels; c) standardized mean difference (SMD) in total bilirubin levels in patients with high vs low CAD severity; and d) correlation between disease severity and total bilirubin. Metaregression analyses were performed to examine the relationship between cardiovascular risk factors and increasing quantiles of total bilirubin levels.

Results

Forty-three studies were identified. Pooled serum total bilirubin levels were 0.72 mg/dl [95% confidence interval (CI): 0.60, 0.83] in MI patients; 0.65 mg/dl [95% CI: 0.60, 0.69] in non-MI CAD patients; and 0.66 mg/dl [95% CI: 0.56, 0.75] in healthy individuals. Higher total bilirubin levels were associated with greater odds of adverse outcomes in MI patients (OR: 1.08 [95% CI: 0.99, 1.18]) but lower odds in non-MI CAD patients (OR: 0.80 [95%CI: 0.73, 0.88]). Compared to non-severe cases, total bilirubin levels were higher in patients with severe MI (SMD 0.96 [95% CI: − 0.10, 2.01]; p = 0.074) but were lower in severe non-MI CAD patients (SMD − 0.30 [95%CI: − 0.56, − 0.03]; p = 0.02). Total bilirubin levels correlated positively with MI severity (r = 0.41 [95% CI: 0.24, 0.59]; p < 0.01) but correlated negatively with non-MI CAD severity (r =  − 0.17 [95% CI: − 0.48, 0.14]; p = 0.28). Female sex was inversely associated with increasing quantiles of bilirubin (meta-regression coefficient: − 8.164 [− 14.531, − 1.769]; p = 0.016) in MI patients.

Conclusion

Prognostic role of bilirubin for CAD appears complicated, as different odds are observed for MI and non-MI CAD patients which weakens the case of causal involvement of bilirubin in CAD etiology or prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02899-w.

Plasma Concentrations of Vinculin versus Talin-1 in Coronary Artery Disease

Vinculin and talin-1, which are cytoskeletal proteins affecting focal adhesions, were reported to be down-expressed in atherosclerotic lesions. Recently, we reported high concentrations of plasma talin-1 in patients with coronary artery disease (CAD). However, blood vinculin concentrations in CAD patients have not been clarified. Plasma vinculin concentrations as well as talin-1 were studied in 327 patients in whom coronary angiography was performed. CAD was proven in 177 patients (1-vessel, n = 79; 2-vessel, n = 57; 3-vessel disease, n = 41). However, vinculin concentrations were not markedly different between the CAD(-) and CAD groups (median 122.5 vs. 119.6 pg/mL, p = 0.325) or among patients with CAD(-), 1-, 2-, and 3-vessel diseases (122.5, 112.8, 107.9, and 137.2 pg/mL, p = 0.202). In contrast, talin-1 concentrations were higher in CAD than the CAD(-) group (0.29 vs. 0.23 ng/mL, p = 0.006) and increased stepwise in the number of stenotic vessels: 0.23 in CAD(-), 0.28 in 1-vessel, 0.29 in 2-vessel, and 0.33 ng/mL in 3-vessel disease (p = 0.043). No correlation was observed between vinculin and talin-1 concentrations. In multivariate analysis, vinculin concentrations were not a factor for CAD. In conclusion, plasma vinculin concentrations in patients with CAD were not high and were not associated with the presence or severity of CAD.

Biliverdin/Bilirubin Redox Pair Protects Lens Epithelial Cells against Oxidative Stress in Age-Related Cataract by Regulating NF-κB/iNOS and Nrf2/HO-1 Pathways

Age-related cataract (ARC) is the leading cause of vision impairment globally. It has been widely accepted that excessive reactive oxygen species (ROS) accumulation in lens epithelial cells (LECs) is a critical risk factor for ARC formation. Biliverdin (BV)/bilirubin (BR) redox pair is the active by-product of heme degradation with robust antioxidative stress and antiapoptotic effects. Thus, we purpose that BV and BR may have a therapeutic effect on ARC. In the present study, we determine the expression levels of enzymes regulating BV and BR generation in human lens anterior capsule samples. The therapeutic effect of BV/BR redox pair on ARC was assessed in hydrogen peroxide (H₂O₂)-damaged mouse LECs in vitro. The NF-κB/inducible nitric oxide synthase (iNOS) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were evaluated to illustrate the molecular mechanism. The results revealed that the mRNA expressions of Nrf2, HO-1, and biliverdin reductase A (BVRA) were all decreased in human samples of age-related nuclear cataract. BV/BR redox pair pretreatment protected LECs against H₂O₂ damage by prohibiting NF-κB p65 nuclear trafficking, ameliorating iNOS expression, reducing intracellular and mitochondrial ROS levels, and restoring glutathione (GSH) and superoxide dismutase (SOD) levels. BV and BR pretreatment also regulated the expression of apoptotic molecules (Bax, Bcl-2, and cleaved caspase-3), thus decreasing the apoptosis of LECs. In addition, BV/BR pair promoted Nrf2 nuclear accumulation and HO-1 induction, whereas the knockdown of BVRA counteracted the effect of BV on activating Nrf2/HO-1 pathway and antiapoptosis. These findings implicated that BV/BR redox pair protects LECs against H₂O₂-induced apoptosis by regulating NF-κB/iNOS and Nrf2/HO-1 pathways. Moreover, BVRA is responsible for BV-mediated cytoprotection by reductive conversion of BV to BR. This trial is registered with ChiCTR2000036059.

Increased Plasma Heme Oxygenase-1 Levels in Patients With Early-Stage Parkinson's Disease

Introduction: Heme oxygenase-1 (HO-1) is a 32 kDa stress-response protein implicated in the pathogenesis of Parkinson’s disease (PD). Biliverdin is derived from heme through a reaction mediated by HO-1 and protects cells from oxidative stress. However, iron and carbon monoxide produced by the catabolism of HO-1 exert detrimental effects on patients with PD. The purpose of this study was to determine whether plasma HO-1 levels represent a biomarker of PD and to further explore the underlying mechanism of increased HO-1 levels by applying voxel-based morphometry (VBM).Methods: We measured plasma HO-1 levels using an enzyme-linked immunosorbent assay (ELISA) in 156 subjects, including 81 patients with early- and advanced-stage PD and 75 subjects without PD. The analyses were adjusted to control for confounders such as age, sex, and medication. We analyzed T1-weighted magnetic resonance imaging (MRI) data from 74 patients with PD using VBM to elucidate the association between altered brain volumes and HO-1 levels. Then, we compared performance on MMSE sub-items between PD patients with low and high levels of HO-1 using Mann-Whitney U tests.Results: Plasma HO-1 levels were significantly elevated in PD patients, predominantly those with early-stage PD, compared with controls (p < 0.05). The optimal cutoff value for patients with early PD was 2.245 ng/ml HO-1 [area under the curve (AUC) = 0.654]. Plasma HO-1 levels were unaffected by sex, age, and medications (p > 0.05). The right hippocampal volume was decreased in the subset of PD patients with high HO-1 levels (p < 0.05). A weak correlation was observed between right hippocampal volume and plasma HO-1 levels (r = −0.273, p = 0.018). There was no difference in total MMSE scores between the low- and high-HO-1 groups (p > 0.05), but the high-HO-1 group had higher language scores than the low-HO-1 group (p < 0.05).Conclusions: Plasma HO-1 levels may be a promising biomarker of early PD. Moreover, a high plasma concentration of the HO-1 protein is associated with a reduction in right hippocampal volume.