Decreased serum fetuin-A levels and active inflammatory bowel disease. Am J Med Sci. 2014;348:47-51. [PMID: 24487480 DOI: 10.1097/maj.0000000000000195]

Loss of Peroxiredoxin IV Protects Mice from Azoxymethane/Dextran Sulfate Sodium-Induced Colorectal Cancer Development

Peroxiredoxin IV (Prx4), a typical two-cysteine-containing member of the peroxidase family, functions as an antioxidant to maintain cellular redox homeostasis through the reduction of reactive oxygen species (ROS) via cycles of oxidation-reduction reactions. Under oxidative stress, all Prxs including Prx4 are inactivated as their catalytic cysteines undergo hyperoxidation, and hyperoxidized two-cysteine Prxs can be exclusively repaired and revitalized through the reduction cycle catalyzed by sulfiredoxin (Srx). Previously, we showed that Prx4 is a preferred substrate of Srx, and knockout of Srx in mice leads to resistance to azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon carcinogenesis. To further understand the significance of the Srx/Prx4 axis in colorectal cancer development, Prx4-/- mice were established and subjected to standard AOM/DSS protocol. Compared with wildtype littermates, mice with Prx4-/- genotype had significantly fewer and smaller tumors. Histopathological analysis revealed that loss of Prx4 leads to increased cell death through lipid peroxidation and lower infiltration of inflammatory cells in the knockout tumors compared to wildtype. Treatment with DSS alone also showed decreased infiltration of macrophages and lymphocytes in the colon of knockout mice, suggesting a role for Prx4 in inflammatory response. In addition, loss of Prx4 caused alterations in plasma cytokines and chemokines after DSS and AOM/DSS treatments. These findings suggest that loss of Prx4 protects mice from AOM/DSS-induced colon tumorigenesis. Thus, targeting Prx4 may provide novel strategies for colon cancer prevention and treatment.

Post-translational modifications glycosylation and phosphorylation of the major hepatic plasma protein fetuin-A are associated with CNS inflammation in children

Fetuin-A is a liver derived plasma protein showing highest serum concentrations in utero, preterm infants, and neonates. Fetuin-A is also present in cerebrospinal fluid (CSF). The origin of CSF fetuin-A, blood-derived via the blood-CSF barrier or synthesized intrathecally, is presently unclear. Fetuin-A prevents ectopic calcification by stabilizing calcium and phosphate as colloidal calciprotein particles mediating their transport and clearance. Thus, fetuin-A plays a suppressive role in inflammation. Fetuin-A is a negative acute-phase protein under investigation as a biomarker for multiple sclerosis (MS). Here we studied the association of pediatric inflammatory CNS diseases with fetuin-A glycosylation and phosphorylation. Paired blood and CSF samples from 66 children were included in the study. Concentration measurements were performed using a commercial human fetuin-A/AHSG ELISA. Of 60 pairs, 23 pairs were analyzed by SDS-PAGE following glycosidase digestion with PNGase-F and Sialidase-AU. Phosphorylation was analyzed in 43 pairs by Phos-TagTM acrylamide electrophoresis following alkaline phosphatase digestion. Mean serum and CSF fetuin-A levels were 0.30 ± 0.06 mg/ml and 0.644 ± 0.55 μg/ml, respectively. This study showed that serum fetuin-A levels decreased in inflammation corroborating its role as a negative acute-phase protein. Blood-CSF barrier disruption was associated with elevated fetuin-A in CSF. A strong positive correlation was found between the CSF fetuin-A/serum fetuin-A quotient and the CSF albumin/serum albumin quotient, suggesting predominantly transport across the blood-CSF barrier rather than intrathecal fetuin-A synthesis. Sialidase digestion showed increased asialofetuin-A levels in serum and CSF samples from children with neuroinflammatory diseases. Desialylation enhanced hepatic fetuin-A clearance via the asialoglycoprotein receptor thus rapidly reducing serum levels during inflammation. Phosphorylation of fetuin-A was more abundant in serum samples than in CSF, suggesting that phosphorylation may regulate fetuin-A influx into the CNS. These results may help establish Fetuin-A as a potential biomarker for neuroinflammatory diseases.

Fetuin-A Deficiency but Not Pentraxin 3, FGF-21, or Irisin, Predisposes to More Serious COVID-19 Course

Analysis of liver biopsy specimens showed that SARS-CoV-2 might have led to liver damage. This study aimed to evaluate the role of selected hepatokines and myokines in the development and progression of COVID-19. Seventy patients with laboratory-confirmed COVID-19 and 20 healthy volunteers were enrolled in the study. Irisin, pentraxin 3, fetuin-A, and FGF-21 serum concentrations and biochemical parameters were assessed using an immunoenzymatic method with commercially available enzyme immunoassay (EIA) or enzyme-linked immunosorbent assay (ELISA) kits. Serum fetuin-A concentrations were significantly decreased in COVID-19 patients compared to healthy volunteers. The serum concentration of FGF-21 was significantly increased in obese COVID-19 patients compared to overweight ones. Moreover, the FGF-21 level was higher in COVID-19 patients diagnosed with metabolic syndrome than in patients without metabolic syndrome. PTX3 concentration was higher in COVID-19 patients with higher HOMA-IR values than those with lower HOMA-IR values. COVID-19 patients with HOMA-IR ≤ 3 and >3 had significantly lower fetuin-A levels than the control group. Irisin concentration was significantly decreased in the HOMA-IR ≤ 3 COVID-19 subgroup when comparing with the control group. Lower levels of fetuin-A observed in COVID-19 patients despite higher HOMA-IR, CRP, and ferritin levels, pneumonia, patients requiring ICU care suggests that fetuin-A deficiency predisposes to more severe COVID-19 course. Upregulated pentraxin 3 may be used as a potential predictor of COVID-19 severity.

Fetuin-A exerts a protective effect against experimentally induced intestinal ischemia/reperfusion by suppressing autophagic cell death

Intestinal tissue is highly susceptible to ischemia/reperfusion injury in many hazardous health conditions. The anti-inflammatory and antioxidant glycoprotein fetuin-A showed efficacy in cerebral ischemic injury; however, its protective role against intestinal ischemia/reperfusion remains elusive. Therefore, this study investigated the protective role of fetuin-A supplementation against intestinal structural changes and dysfunction in a rat model of intestinal ischemia/reperfusion. We equally divided 72 male rats into control, sham, ischemia/reperfusion, and fetuin-A-pretreated ischemia/reperfusion (100 mg/kg/day fetuin-A intraperitoneally for three days prior to surgery and a third dose 1 h prior to the experiment) groups. After 2 h of reperfusion, the jejunum was dissected and examined for spontaneous contractility. A jejunal homogenate was used to assess inflammatory and oxidative stress enzymes. Staining of histological sections was carried out with hematoxylin, eosin and Masson's trichrome stain for evaluation. Immunohistochemistry was performed to detect autophagy proteins beclin-1, LC3, and p62. This study found that fetuin-A significantly improved ischemia/reperfusion-induced mucosal injury by reducing the percentage of areas of collagen deposition, increasing the amplitude of spontaneous contraction, decreasing inflammation and oxidative stress, and upregulating p62 expression, which was accompanied by beclin-1 and LC3 downregulation. Our findings suggest that fetuin-A treatment can prevent ischemia/reperfusion-induced jejunal structural and functional changes by increasing antioxidant activity and regulating autophagy disturbances observed in the ischemia/reperfusion rat model. Furthermore, fetuin-A may provide a protective influence against intestinal ischemia/reperfusion complications.

α2-Heremans-schmid glycoprotein (fetuin A) downregulation and its utility in inflammatory bowel disease

AIM

To investigate the impact of inflammatory bowel disease (IBD) on α2-Heremans-Schmid Glycoprotein (AHSG/fetuin A) and potential associations with disease and patient characteristics.

METHODS

AHSG serum levels were determined in treatment-naïve newly-diagnosed patients, 96 with ulcerative colitis (UC), 84 with Crohn's disease (CD), 62 with diarrhea-predominant or mixed irritable bowel syndrome (IBS, D- and M- types) and 180 healthy controls (HC), by an enzyme linked immunosorbent assay (ELISA). All patients were followed for a minimum period of 3 years at the Gastroenterology Department of the University Hospital of Larissa, Greece. C-reactive protein (CRP), anti-glycan antibodies, anti-Saccharomyces cerevisiae mannan antibodies IgG, anti-mannobioside carbohydrate antibodies IgG, anti-laminariobioside carbohydrate antibodies IgG and anti-chitobioside carbohydrate antibodies IgA were also determined via immunonephelometry and ELISA, respectively.

RESULTS

The mean ± SE of serum AHSG, following adjustment for confounders, was 0.32 ± 0.02 g/L in IBD, 0.32 ± 0.03 g/L in CD and 0.34 ± 0.03 g/L in UC patients, significantly lower than in IBS patients (0.7 ± 0.018 g/L) and HC (0.71 ± 0.02 g/L) (P < 0.0001, in all cases). AHSG levels were comparable between the CD and UC groups. Based on AHSG levels IBD patients could be distinguished from HC with about 90% sensitivity and specificity. Further adjusted analysis verified the inverse association between AHSG and penetrating, as well as stricturing CD (partial correlation coefficient: -0.45 and -0.33, respectively) (P < 0.05). After adjusting for confounding factors, inverse correlations between AHSG and CRP and the need for anti-TNFα therapy or surgery, were found (partial correlation coefficients: -0.31, -0.33, -0.41, respectively, P < 0.05, in all cases). Finally, IBD individuals who were seropositive, for at least one marker, had AHSG levels falling within the two lower quartiles (OR = 2.86, 95%CI: 1.5-5.44, P < 0.001) while those with at least two serological markers positive exhibited AHSG concentrations within the lowest quartile (OR = 5.03, 95%CI: 2.07-12.21, P < 0.001), after adjusting for age, sex and smoking.

CONCLUSION

AHSG can be used to distinguish between IBD and IBS patients or HC while at the same time "predicting" complicated disease behavior, need for therapy escalation and surgery. Moreover, AHSG may offer new insights into the pathogenesis of IBD, since it is involved in key processes.

Blood-borne phagocytes internalize urate microaggregates and prevent intravascular NETosis by urate crystals

Hyperuricemia is strongly linked to cardiovascular complications including atherosclerosis and thrombosis. In individuals with hyperuricemia, needle-shaped monosodium urate crystals (nsMSU) frequently form within joints or urine, giving rise to gouty arthritis or renal calculi, respectively. These nsMSU are potent instigators of neutrophil extracellular trap (NET) formation. Little is known on the mechanism(s) that prevent nsMSU formation within hyperuricemic blood, which would potentially cause detrimental consequences for the host. Here, we report that complement proteins and fetuins facilitate the continuous clearance by blood-borne phagocytes and resident macrophages of small urate microaggregates (UMA; <1 μm in size) that initially form in hyperuricemic blood. If this clearance fails, UMA exhibit bipolar growth to form typical full-sized nsMSU with a size up to 100 μm. In contrast to UMA, nsMSU stimulated neutrophils to release NETs. Under conditions of flow, nsMSU and NETs formed densely packed DNase I-resistant tophus-like structures with a high obstructive potential, highlighting the importance of an adequate and rapid removal of UMA from the circulation. Under pathological conditions, intravascularly formed nsMSU may hold the key to the incompletely understood association between NET-driven cardiovascular disease and hyperuricemia.

Total and cancer mortality in a cohort of ulcerative colitis and Crohn's disease patients: The Florence inflammatory bowel disease study, 1978-2010

BACKGROUND

There is no consensus on the leading causes of death among inflammatory bowel diseases (IBD) patients.

AIM

We present the results of an extended follow-up of the population-based Florence IBD cohort, including 689 ulcerative colitis and 231 Crohn's disease patients.

METHODS

The causes of death of cohort members were determined through linkage with the local mortality registry. We calculated standardized mortality ratios (SMR) and 95% confidence intervals (95%CI) by applying gender-, age- and calendar time-death rates to person-years at risk.

RESULTS

Ulcerative colitis patients had overall mortality comparable to the general population (SMR 0.99, 95%CI 0.85-1.14), though being at increased risk of dying from Hodgkin's disease (SMR 11.74, 95%CI 2.94-46.94), rectal cancer (SMR 3.69, 95%CI 1.66-8.22) and Alzheimer's disease (2.40, 95%CI 1.00-5.76). Crohn's disease patients had an increased overall mortality (SMR 1.79, 95%CI 1.39-2.27) and were at higher risk of dying from cancer (SMR 2.57, 95%CI 1.28-5.13) and non-cancer diseases of the respiratory system (SMR 2.51, 95%CI 1.05-6.04), brain cancer (SMR 6.26, 95%CI 1.57-25.02) and non-cancer diseases of the genitourinary system (SMR 4.38, 95%CI 1.10-17.52).

CONCLUSIONS

IBD patients should be offered counselling on risk reduction strategies, as much of their mortality excess is potentially avoidable.