Dysregulation of platelet serotonin, 14-3-3, and GPIX in sudden infant death syndrome

Sudden infant death syndrome (SIDS) is the leading cause of post-neonatal infant mortality, but the underlying cause(s) are unclear. A subset of SIDS infants has abnormalities in the neurotransmitter, serotonin (5-hydroxytryptamine [5-HT]) and the adaptor molecule, 14-3-3 pathways in regions of the brain involved in gasping, response to hypoxia, and arousal. To evaluate our hypothesis that SIDS is, at least in part, a multi-organ dysregulation of 5-HT, we examined whether blood platelets, which have 5-HT and 14-3-3 signaling pathways similar to brain neurons, are abnormal in SIDS. We also studied platelet surface glycoprotein IX (GPIX), a cell adhesion receptor which is physically linked to 14-3-3. In infants dying of SIDS compared to infants dying of known causes, we found significantly higher intra-platelet 5-HT and 14-3-3 and lower platelet surface GPIX. Serum and plasma 5-HT were also elevated in SIDS compared to controls. The presence in SIDS of both platelet and brainstem 5-HT and 14-3-3 abnormalities suggests a global dysregulation of these pathways and the potential for platelets to be used as a model system to study 5-HT and 14-3-3 interactions in SIDS. Platelet and serum biomarkers may aid in the forensic determination of SIDS and have the potential to be predictive of SIDS risk in living infants.

Diagnostic and Prognostic Value of Plasma GFAP in Sporadic Creutzfeldt-Jakob Disease in the Clinical Setting of Rapidly Progressive Dementia

The diagnostic and prognostic value of plasma glial fibrillary acidic protein (pl-GFAP) in sporadic Creutzfeldt-Jakob disease (sCJD) has never been assessed in the clinical setting of rapidly progressive dementia (RPD). Using commercially available immunoassays, we assayed the plasma levels of GFAP, tau (pl-tau), and neurofilament light chain (pl-NfL) and the CSF total tau (t-tau), 14-3-3, NfL, phospho-tau181 (p-tau), and amyloid-beta isoforms 42 (Aβ42) and 40 (Aβ40) in sCJD (n = 132) and non-prion RPD (np-RPD) (n = 94) patients, and healthy controls (HC) (n = 54). We also measured the CSF GFAP in 67 sCJD patients. Pl-GFAP was significantly elevated in the sCJD compared to the np-RPD and HC groups and affected by the sCJD subtype. Its diagnostic accuracy (area under the curve (AUC) 0.760) in discriminating sCJD from np-RPD was higher than the plasma and CSF NfL (AUCs of 0.596 and 0.663) but inferior to the 14-3-3, t-tau, and pl-tau (AUCs of 0.875, 0.918, and 0.805). Pl-GFAP showed no association with sCJD survival after adjusting for known prognostic factors. Additionally, pl-GFAP levels were associated with 14-3-3, pl-tau, and pl-NfL but not with CSF GFAP, Aβ42/Aβ40, and p-tau. The diagnostic and prognostic value of pl-GFAP is inferior to established neurodegeneration biomarkers. Nonetheless, pl-GFAP noninvasively detects neuroinflammation and neurodegeneration in sCJD, warranting potential applications in disease monitoring.

Prospective Role of PAK6 and 14-3-3γ as Biomarkers for Parkinson's Disease

Background

Parkinson's disease is a progressive neurodegenerative disorder mainly distinguished by sporadic etiology, although a genetic component is also well established. Variants in the LRRK2 gene are associated with both familiar and sporadic disease. We have previously shown that PAK6 and 14-3-3γ protein interact with and regulate the activity of LRRK2.

Objective

The aim of this study is to quantify PAK6 and 14-3-3γ in plasma as reliable biomarkers for the diagnosis of both sporadic and LRRK2-linked Parkinson's disease.

Methods

After an initial quantification of PAK6 and 14-3-3γ expression by means of Western blot in post-mortem human brains, we verified the presence of the two proteins in plasma by using quantitative ELISA tests. We analyzed samples obtained from 39 healthy subjects, 40 patients with sporadic Parkinson's disease, 50 LRRK2-G2019S non-manifesting carriers and 31 patients with LRRK2-G2019S Parkinson's disease.

Results

The amount of PAK6 and 14-3-3γ is significantly different in patients with Parkinson's disease compared to healthy subjects. Moreover, the amount of PAK6 also varies with the presence of the G2019S mutation in the LRRK2 gene. Although the generalized linear models show a low association between the presence of Parkinson's disease and PAK6, the kinase could be added in a broader panel of biomarkers for the diagnosis of Parkinson's disease.

Conclusions

Changes of PAK6 and 14-3-3γ amount in plasma represent a shared readout for patients affected by sporadic and LRRK2-linked Parkinson's disease. Overall, they can contribute to the establishment of an extended panel of biomarkers for the diagnosis of Parkinson's disease.

Comparison of Serum Levels of 14-3-3 ETA Proteins between Rheumatoid Arthritis, Osteoarthritis and Normal Controls

14-3-3 ETA protein, a joint-derived biomarker that up-regulates inflammatory cytokines which enhances local and systemic inflammation and may lead to destructive changes in joints, is thought to be a good diagnostic marker for early RA. To assess the usefulness of serum levels of 14-3-3 ETA in the diagnosis of RA. This is a case-control study which involved 3 groups: group 1 included 30 RA patients, group 2 included 30 primary osteoarthritis patients and group 3 included 30 healthy controls. All study subjects were assessed using laboratory investigations as CBC, ESR, CRP, RF, ACPA as well as serum levels of 14-3-3 ETA protein which were measured through ELISA technique. Mean ± SD levels of 14-3-3 ETA were significantly higher among RA compared to OA and control groups (0.7(0.5), 0.2 (0.1) and 0.3(0.1) ng/ml, respectively) with a sensitivity of 79.3%, specificity of 81.7%, positive predicted value of 86% and negative predicted value of 81%. 14-3-3 ETA also had high diagnostic OR (1478.04). A statistically significant correlation (r= 0.259) was found between serum levels of 14-3-3 ETA and ESR. In conclusion, 14-3-3 ETA is a novel marker for RA that should be used in conjunction with RF and ACPA for diagnosis of the disease.

Importance of 14-3-3eta, anti-CarP, and anti-Sa in the diagnosis of seronegative rheumatoid arthritis

Background/aim

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation. The study aimed to assess serum 14-3-3eta, anti-CarP, and anti-Sa in seronegative RA (SNRA) patients who were treatment-naïve as well as in healthy subjects. This is the first study in the literature to examine these autoantibodies together in SNRA patients.

Materials and methods

Forty-five treatment-naïve SNRA patients and 45 healthy subjects were recruited. Drugs change the levels of autoantibodies; therefore, patients who took any medication had been excluded from our study. Anti-carbamylated protein, anti-Sa, and 14-3-3eta were measured by using three different ELISA kits.

Results

Median serum concentration of healthy controls in 14-3-3eta was 0.02 (0.02–0.27) ng/mL. Median serum concentration of SNRA patients in 14-3-3eta was 1.00 (0.48–1.28) ng/mL. Data were analyzed with Mann–Whitney U tests; the P-value was <0.001 in 14-3-3eta. Receiver operating characteristic (ROC) curve analysis showed that 14-3-3eta in SNR compared to healthy controls had a significant (P < 0.001) area under the curve (AUC) of 0.90 (95% confidence interval, 0.83–0.96). At a cutoff of ≥0.33 ng/mL, the ROC curve yielded a sensitivity of 88.9%, a specificity of 82.2%, a positive predictive value of 83.3%, and a negative predictive value of 88.1%.

Conclusion

We found that 14-3-3eta can be used as a diagnostic marker in SNRA.

Evaluation of Serum Protein 14-3-3η (Eta) as a Novel Biomarker for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is one of the most common systemic autoimmune diseases. New markers are needed for early diagnosis of RA as seronegativity in both early and established RA remains a major limitation of both anticitrullinated protein antibodies (ACPA) and rheumatoid factor (RF). The 14-3-3η protein may represent a novel biomarker for the detection of RA. We evaluated the diagnostic performance of serum 14-3-3η protein in early and established cases of rheumatoid arthritis and we compared the diagnostic accuracy of it with those of the well-known RA markers (e.g. RF and ACPA). Sera from 50 patients with RA (20 early and 30 established) based on the 2010 ACR / EULAR Rheumatoid Arthritis Classification Criteria, 15 patients with non-RA arthritis as diseases control group (8 patients with OA and 7 patients with SLE) and 14 healthy controls were enrolled in the study. Serum RF was determined by latex, ACPA and 14-3-3η protein were determined by ELISA. Serum 14-3-3η protein levels in patients with RA were significantly higher (P=0.001*) as compared to healthy individuals. For serum 14-3-3η diagnostic accuracy in RA; Receiver operating characteristic curves (ROC) analysis comparing patient with RA with healthy control showed AUC (0.916) at optimum cutoff of > 2.5ng/mL, and a sensitivity of 100%, a specificity of 78.57%, a PPV of 94.3, and an NPV of 100. No significant difference in 14-3-3η protein serum levels was found between early and established RA groups. It was positive in 100% of early and established RA patients who were seronegative for RF and ACPA. It is concluded that, 14-3-3η protein could improve the sensitivity of RA diagnosis and cover the shortage of detection of RF and ACPA in RA patients.

Serum 14-3-3η Could Improve the Diagnostic Rate of Rheumatoid Arthritis and Correlates to Disease Activity

OBJECTIVES

Serum 14-3-3η is a novel joint-derived proinflammatory mediator associated with rheumatoid arthritis (RA). This study aimed to evaluate the diagnostic capacity of serum 14-3-3η and its correlation with clinical variables in patients with RA.

METHODS

A total of 94 patients with RA and 80 age- and sex-matched controls, including 40 healthy subjects, were included. Serum 14-3-3η levels were assessed by quantitative enzyme-linked immunosorbent assay. Receiver-operating characteristic (ROC) curves analysis was used to determine the sensitivity and specificity of 14-3-3η. Spearman's rank correlation coefficient was used to assess the relationship between 14-3-3η and other clinical measures in patients with RA.

RESULTS

Median (interquartile range) of serum 14-3-3η concentration (ng/ml) in RA patients (2.34 [1.56-3.39]) was significantly higher than that in healthy subjects (0.17[0.11-0.30]) and disease controls (1.66[1.21-2.74]; P<0.05). ROC curve analysis comparing patients with RA with all controls demonstrated a significant (P<0.001) area under the curve (AUC) of 0.81 (95% confidence interval: 0.74-0.88). At a cutoff of 1.44 ng/mL, the ROC curve yielded a sensitivity of 78.7% and specificity of 73.8%. The sensitivity of anti-citrullinated protein antibody (ACPA) and rheumatoid factor (RF) were 84.0% and 72.3%, respectively. Adding 14-3-3η to ACPA and/or RF discriminated more than 96% of patients with RA. The positive rate of at least one of the three markers was up to 99%, with a specificity of about 70%. The results of correlation analyses revealed that serum levels of 14-3-3η protein positively correlated with C-reactive protein (r=0.250, P<0.05), erythrocyte sedimentation rate (r=0.294, P<0.01), and 28-joint disease activity score (r=0.275, P<0.05) in patients with RA.

CONCLUSIONS

14-3-3η protein is a novel marker that can apparently enhance the detection rate of patients with RA. The level of serum 14-3-3η protein correlates to some degree with disease activity.

14-3-3η: a novel biomarker platform for rheumatoid arthritis

14-3-3 proteins are a conserved family of 7 isoforms with diverse cellular functions found predominantly intracellularly. The 14-3-3η isoform is expressed extracellularly in the joints of patients with rheumatoid arthritis (RA) and expression in both serum and joint fluid correlates strongly with expression of metalloproteinases. 14-3-3η activates proinflammatory signalling cascades and inflammatory mediators relevant to the pathogenesis of RA. A new ELISA based assay has diagnostic utility for RA with sensitivity of 63.6% and specificity of 92.6% using the optimal cut-off from ROC analysis of 0.19ng/ml. Adding 14-3-3η to anti-cyclic citrullinated peptide antibodies (ACPA) resulted in an identification rate of 72% compared to 59% for ACPA alone. Adding rheumatoid factor (RF) to ACPA increased diagnostic capture from 59% to 72% and this increased further to 78% when 14-3-3η was added. Positive 14-3-3η status is also significantly associated with radiographic progression in early RA at years 1, 3 and 5 indicating prognostic utility. Extracellular 14-3-3η elicits the production of autoantibodies to the native protein, which also possess diagnostic utility. These do not correlate with expression of the protein and have complementary diagnostic utility. The presence of either the protein or its autoantibodies is observed in 90% of patients with early RA. Together with RF and/or ACPA this may result in identification of 95% of patients with early RA.

[Characterization and preliminary application of six monoclonal antibodies against recombinant signal protein 14-3-3 of Schistosoma japonicum]

OBJECTIVES

To identify the properties of six monoclonal antibodies (McAbs) against recombinant signal protein 14-3-3 of Schistosoma japonicum, and investigate their value in the diagnosis of schistosomiasis.

METHODS

The subclasses, titers, affinity-constants, detection limits and specificities of six McAbs were identified by ELISA and Western blotting. Dot Enzyme-linked Immunosorbent Assay (Dot-ELISA) for detecting the 14-3-3 protein in the sera of rabbits infected with Schistosoma japonicum was established, then it was used to observe the dynamics of 14-3-3 protein in sera of rabbits infected with Schistosoma japonicum before and after treatment. The diagnostic value of Dot-ELISA was investigated through detecting a group of sera samples of rabbits infected with Schistosoma japonicum.

RESULTS

The types of six McAbs against recombinant signal protein 14-3-3 of Schistosoma japonicum of 3F1, 3F7, 5C6, 5D1, 5G9 and 1G6 were all IgG, their subclasses were IgG1, IgG2a, IgG2b, IgG1, IgG1 and IgG1, their antibody-titers in ascites were 1:6.4 x 10(5), 1:8.0 x 10(5) , 1:6.4 x 10(5), 1:3.2 x 10(5), 1:4.8 x 10(5) and 1:2.0 x 10(4), their affinity-constants were 8.82 x 10(8), 4.93 x 10(8), 1.56 x 10(8), 5.12 x 10(8), 1.41 x 10(8) moL/L and 2.30 x 10(7) mol/L, their detection limits in dot-ELISA were 1, 10, 100, 10, 10, 100 ng, respectively. All the six McAbs recognized the recombinant signal protein 14-3-3 of Schistosoma japonicum and the natural signal protein 14-3-3 in SEA, ESA and AWA, and did not react with the protein of E. coli and Clonorchis sinensis in Western blotting. 3F1 and 5D1 were selected to establish the Dot- ELISA for detecting the sera of rabbits infected with Schistosoma japonicum before and after treatment at different time points, it was found that the concentration of 14-3-3 protein in sera of rabbits was increased gradually with time and decreased gradually after the infected rabbits treated with praziquantel. Forty-two sera samples of rabbits infected with Schistosoma japonicum were detected by this Dot-ELISA, 41 samples were positive, the sensitivity was 97.6%, and all of the ten healthy rabbits' sera were negative, the specificity was 100%.

CONCLUSIONS

All the six McAbs could recognize natural signal protein 14-3-3. It has been proved preliminarily that the Dot-ELISA based on 3F1 and 5D1 is valuable for the diagnosis of active infection of Schistosoma japonicum and accessing the chemotherapeutic effect of schistosomiasis.

Serum 14-3-3; matrix metalloproteinases and their inhibitors' levels before and after cardiovascular surgery in diabetic and non-diabetic patients

AIMS

We sought to assess the serum levels of the main extracellular matrix components before and after surgery in order to differentiate the response of diabetic patients to acute wounds from that of non-diabetic patients.

METHODS

The serum levels of 14-3-3, Pro-MMP-1, MMP-3, and TIMP-1 were measured in diabetics (18 patients) and non-diabetics (22 patients) in samples obtained before a coronary artery bypass grafting operation and on the 1st, 3rd, and 5th postoperative days.

RESULTS

The diabetics had higher serum levels of 14-3-3 both in the pre- and postoperative phases. Nevertheless, there was a postoperative drop in these amounts in all the patients. There was no difference in the serum levels of Pro-MMP-1 between the two groups. In addition, the serum levels of MMP-3 on the 3rd and 5th postoperative days and also TIMP-1 (inhibitor of both MMPs) on all postoperative days were higher in the diabetics.

CONCLUSIONS

There was perfect synchronicity between the changes in the serum levels of these proteins and their functional nature in the injured tissue. Furthermore, the diabetic patients exhibited more changes in the levels of some of their extracellular enzymes in the wake of acute wounds; these changes were also traceable in the serum.

Platelet activation by dimeric beta2-glycoprotein I requires signaling via both glycoprotein Ibalpha and apolipoprotein E receptor 2'

BACKGROUND

Dimerization of beta(2)-glycoprotein I (beta(2)-GPI) by autoantibodies is thought to trigger the clinical manifestations observed in the antiphospholipid syndrome. Arterial thrombosis, a frequently occurring clinical manifestation of the antiphospholipid syndrome, is a process in which platelets play a crucial role. Previous work has shown that binding of dimeric beta(2)-GPI to the platelet receptors apolipoprotein E receptor 2' (ApoER2') and glycoprotein Ibalpha (GPIbalpha) mediates increased platelet activation in an in vitro thrombosis model.

OBJECTIVE

The individual roles of ApoER2' and GPIbalpha in mediating platelet activation by dimeric beta(2)-GPI has hitherto been unclear. In this study, we have determined the roles of either receptor in platelet activation by dimeric beta(2)-GPI.

METHODS

Platelet activation by dimeric beta(2)-GPI was studied under conditions of flow. Intracellular signaling induced by dimeric beta(2)-GPI was subsequently analyzed by means of sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and western blot analysis.

RESULTS

The increase in platelet deposition onto a fibronectin surface under conditions of flow by dimeric beta(2)-GPI was completely abolished by inhibition of the interaction of dimeric beta(2)-GPI with either GPIbalpha or ApoER2'. Upon platelet stimulation with dimeric beta(2)-GPI, GPIbalpha translocated to the cytoskeleton via the scaffold protein 14-3-3zeta. Concomitantly, ApoER2' dissociated from the adapter protein Disabled1, presumably through phosphorylation of the cytoplasmic tail. Inhibition of one process could not inhibit the other.

CONCLUSION

We show that dimeric beta(2)-GPI signals via two distinct pathways in platelets, both of which are required for platelet activation. Abrogation of either signal results in loss of activation.