CD142 promotes trophoblast cell migration by inhibiting BCL2-related autophagic degradation of IL-8

The maintenance of migration of trophoblast cells is beneficial to pregnancy, and its weakening can lead to preeclampsia (PE). CD142 is considered as a classical motility-promoting factor. Our research aimed to explore the role of CD142 in trophoblast cell migration and potential mechanism. Through fluorescence-activated cell sorting (FACS) and gene transduction assays, CD142 expression levels of mouse trophoblast cell lines were upregulated and downregulated respectively. Then, the migratory level was detected through Transwell assays in different groups of trophoblast cells. The corresponding chemokines were screened by ELISA in different sorted trophoblast cells. Based on gene overexpression and knockdown assays, the production mode of identified valuable chemokine was analyzed by detecting gene and protein expression in trophoblast cells. Finally, the contribution of autophagy response to specific chemokine regulated by CD142 was explored by combining different groups of cells and autophagy regulators. Our results showed that both CD142 positive sorting and CD142 overexpression promoted the migratory ability of trophoblast cells, and trophoblast cells with the highest level of CD142 had the strongest migratory ability. In addition, CD142+ cells contained the highest level of IL-8. Consistently, CD142 overexpression promoted IL-8 protein expression in trophoblast cells while CD142 silencing was contrary. However, both CD142 overexpression and CD142 silencing did not affect IL-8 mRNA expression. Moreover, both CD142+ and CD142-overexpressed cells showed higher BCL2 protein expression and poorer autophagic activity. Importantly, autophagy activation with TAT-Beclin1 recovered the increased IL-8 protein expression in CD142+ cells. Obviously, the migratory ability of CD142+ cells inhibited by TAT-Beclin1 was recovered by the addition of IL-8 recombinant factor. In conclusion, CD142 inhibits the degradation of IL-8 through the inhibition of BCL2-Beclin1-autophagy signal transduction, thereby promoting the migration of trophoblast cells.

CD142 plays a key role in the carcinogenesis of gastric adenocarcinoma by inhibiting BCL2-dependent autophagy

CD142 is expressed on the surface of multiple malignant tumors and contributes to various carcinogenesis. However, the role of CD142 in the pathogenesis of GAC remains unclear. This study aimed to investigate the role of CD142 in GAC carcinogenesis. Our results showed that CD142 expression was significantly increased in GAC cancer tissues, especially in those with significant invasion or metastasis. The invasion and migration of CD142-positive SNU16 cells were significantly increased compared with those of CD142-negative cells. Moreover, CD142 overexpression promoted the invasion and migration of SGC083 cells, but CD142 silencing was contrary. In addition, there was a positive correlation between CD142 expression of cancer tissues and serum IL-8 levels. CD142 overexpression promotes IL-8 production in SGC083 cells. In vivo analysis showed that the implantation of CD142-positive SNU16 cells promoted the growth of xenograft tumor and the production of IL-8. Mechanistically, CD142 silencing not only inhibited the expression of BCL2 and the interaction between BCL2 and Beclin1, but also promoted the autophagic response in SGC083. Furthermore, CD142 silencing-induced IL-8 degradation was recovered by treatment of autophagy inhibitor 3-MA. CD142 can inhibit autophagic cell death and the autophagic degradation of IL-8 in GAC, which exerts an effective effect on GAC carcinogenesis.

Molecular Mechanisms of "Antiphospholipid Antibodies" and Their Paradoxical Role in the Pathogenesis of "Seronegative APS"

Antiphospholipid Syndrome (APS) is an autoimmune disease characterized by arterial and/or venous thrombosis and/or pregnancy morbidity, associated with circulating antiphospholipid antibodies (aPL). In some cases, patients with a clinical profile indicative of APS (thrombosis, recurrent miscarriages or fetal loss), who are persistently negative for conventional laboratory diagnostic criteria, are classified as "seronegative" APS patients (SN-APS). Several findings suggest that aPL, which target phospholipids and/or phospholipid binding proteins, mainly β-glycoprotein I (β-GPI), may contribute to thrombotic diathesis by interfering with hemostasis. Despite the strong association between aPL and thrombosis, the exact pathogenic mechanisms underlying thrombotic events and pregnancy morbidity in APS have not yet been fully elucidated and multiple mechanisms may be involved. Furthermore, in many SN-APS patients, it is possible to demonstrate the presence of unconventional aPL ("non-criteria" aPL) or to detect aPL with alternative laboratory methods. These findings allowed the scientists to study the pathogenic mechanism of SN-APS. This review is focused on the evidence showing that these antibodies may play a functional role in the signal transduction pathway(s) leading to thrombosis and pregnancy morbidity in SN-APS. A better comprehension of the molecular mechanisms triggered by aPL may drive development of potential therapeutic strategies in APS patients.

A woman with systemic lupus erythematosus, multiple pregnancy complications, and cerebral infarction who was only positive for phosphatidylserine-dependent antiprothrombin antibodies

A woman with systemic lupus erythematosus (SLE) had a history of two abortions before the 10th week, two foetal deaths with normal morphology, and one premature before the 34th week with early-onset hypertensive disorder of pregnancy (HDP) and placental dysfunction. Although she did not have any conventional antiphospholipid antibodies (aPLs), antiphospholipid syndrome (APS) was strongly suspected based on her obstetric history and renal biopsy findings consistent with aPL-associated nephropathy (APLN). Eventually, she was found to be positive for phosphatidylserine-dependent antiprothrombin antibodies (aPS/PTs). A healthy baby was born with anticoagulation and intravenous immunoglobulin (IVIG) therapy during pregnancy. aPS/PT titres gradually increased after delivery. Cerebral infarction occurred at 9 years after birth. If APS is clinically suspected but the antibodies included in the classification criteria for APS are all negative, we should consider an association with unconventional aPLs and manage according to APS.

Antiphosphatidylserine/prothrombin complex antibodies as a determinant of prothrombotic plasma fibrin clot properties in patients with antiphospholipid syndrome

BACKGROUND

Antiphosphatidylserine/prothrombin complex (aPS/PT) antibodies are recognized as a marker for antiphospholipid syndrome (APS). Dense and poorly lysable fibrin clots occur in thrombotic APS. Compact clots predict thromboembolism, but determinants of the unfavorable clot phenotype remain unknown in APS. We hypothesized that elevated aPS/PT antibodies determine unfavorable clot features.

METHODS

In a cohort study involving 124 consecutive patients with thrombotic APS, we measured at baseline plasma fibrin clot permeability (Ks ), efficiency of fibrinolysis (clot lysis time, CLT), and turbidity (off anticoagulation) along with immunoglobulin (Ig)G/IgM aPS/PT. During follow-up, symptomatic thromboembolic events were recorded.

RESULTS

Elevated IgG and IgM aPS/PT antibodies >30 international enzyme units (UI) were detected in 54.8% and 42.7% of APS patients, including 76.2% and 54% of lupus anticoagulant- (LA, n = 63) positive patients, respectively. Elevated IgG and IgM aPS/PT antibodies predicted low Ks (lower quartile, <6 × 10-9  cm2 ; odds ratio [OR] = 5.93, 95% confidence interval [CI] 2.09-16.82 and OR = 11.79, 95% CI 4.10-33.92) and prolonged CLT (top quartile, ≥116 min; OR = 4.85, 95% CI 2.42-25.07 and OR = 6.04, 95% CI 2.42-15.07). No such associations were observed for anticardiolipin or β2-glycoprotein I antibodies or LA presence. During follow-up (median 72.5, range 66-83 months), thromboembolic events observed in 32 (26.7%, 4.6%/year) patients were independently predicted by IgG aPS/PT antibodies >30 UI (hazard ratio [HR] = 3.04, 95% CI 1.20-8.88) and low Ks (HR = 3.00, 95% CI 1.41-6.50).

CONCLUSIONS

We identified aPS/PT antibodies as a determinant of denser and poorly lysable plasma fibrin clot formation in APS patients. The association of elevated aPS/PT antibodies with thromboembolism in APS could be at least in part mediated by prothrombotic clot properties.

Anti-β2-glycoprotein I and anti-phosphatidylserine/prothrombin antibodies exert similar pro-thrombotic effects in peripheral blood monocytes and endothelial cells

Purpose

The introduction of the anti-phosphatidylserine/prothrombin (aPS/PT) antibodies among the routinely investigated anti-phospholipid (aPL) antibodies led to an improvement in anti-phospholipid syndrome (APS) laboratory diagnostic performance; however, their pathogenic mechanism is still substantially undefined. To support clinical data and future inclusion as possible new criteria antibodies, we designed a head-to-head study to directly compare the procoagulant effects sustained in vitro by aPS/PT to those sustained by anti-β2-glycoprotein I (aβ2GpI) domain 1-specific antibodies.

Methods

Blood donors-derived monocytes and endothelial cells (HUVEC) were stimulated with lipopolysaccharides (LPS) alone or in combination with the IgG fractions isolated from the serum of six APS patients, positive only for aβ2GpI or for aPS/PT antibodies. As control, cells were incubated with LPS plus the IgG isolated from blood donors. Tissue factor (TF) mRNA expression was measured after four hours incubation by real-time PCR. Nitric oxide (NO) levels were measured in cells supernatant after 16 h incubation by colorimetric assay.

Results

aPS/PT and aβ2GpI IgG antibodies fractions showed comparable ability to enhance LPS-induced TF mRNA expression, either in monocytes and in HUVEC. Compared to LPS alone, we found that NO levels are strongly overproduced in HUVEC treated with LPS plus aβ2GpI and aPS/PT IgG fractions.

Conclusions

Our data support the significant and independent role of aPS/PT in the pathogenesis of the thrombotic events in APS patients, possibly adding new light to the therapeutic management of cases characterized by the sole presence of aPS/PT IgG antibodies.

Electronic supplementary material

The online version of this article (10.1186/s13317-019-0113-9) contains supplementary material, which is available to authorized users.

Insights into the diagnosis and pathogenesis of the antiphospholipid syndrome

The Antiphospholipid syndrome (APS), formerly known as Anticardiolipin or Hughes syndrome, is a systemic autoimmune disorder characterized by obstetrical complications and thrombotic events affecting almost every organ-system in patients persistently testing positive for antiphospholipid antibodies (aPL). The contribution of the extra-criteria aPL to the pathogenesis of APS have exceeded the expectations of a simple, direct pathologic 'hit' leading to thrombogenesis or obstetrical complications, and more pathologic pathways are being linked directly or indirectly to aPL. The value of extra-criteria aPL is on the rise, and these antibodies are nowadays evaluated as markers for risk assessment in the diagnostic approach to APS. A diagnosis of APS should be considered in pediatric patients with suggestive clinical and laboratory picture. Management of APS remains mostly based on anticoagulation, while other drugs are being tested for efficacy and side effects. Low-dose aspirin may have a role in the management of thrombotic and obstetric APS. Due to the high variability in disease severity and complication recurrence outcomes, new tools are being developed and validated to assess the damage index and quality of life of APS patients.

How to Identify High-Risk APS Patients: Clinical Utility and Predictive Values of Validated Scores

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS) is a clinical disorder characterised by thrombosis and/or pregnancy morbidity in the persistence of antiphospholipid (aPL) antibodies that are pathogenic and have pro-coagulant activities. Thrombosis in APS tends to recur and require prophylaxis; however, the stereotypical treatment for APS patients is inadequate and stratification of the thrombotic risks is important as aPL are prevalently observed in various diseases or elderly population.

RECENT FINDINGS

It is previously known that the multiple positive aPL or high titre aPL correlate to thrombotic events. To progress the stratification of thrombotic risks in APS patients and to quantitatively analyse those risks, antiphospholipid score (aPL-S) and the Global Anti-phospholipid Syndrome Score (GAPSS) were defined. These scores were raised from the large patient cohort data and either aPL profile classified in detail (aPL-S) or simplified aPL profile with classical thrombotic risk factors (GAPSS) was put into a scoring system. Both the aPL-S and GAPSS have shown a degree of accuracy in identifying high-risk APS patients, especially those at a high risk of thrombosis. However, there are several areas requiring improvement, or at least that clinicians should be aware of, before these instruments are applied in clinical practice. One such issue is standardisation of the aPL tests, including general testing of phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT). Additionally, clinicians may need to be aware of the patient's medical history, particularly with respect to the incidence of SLE, which influences the cutoff value for identifying high-risk patients.

Antiphosphatidylserine/prothrombin (aPS/PT) antibodies are associated with Raynaud phenomenon and migraine in primary thrombotic antiphospholipid syndrome

Objectives

Antibodies to phosphatidylserine/prothrombin complex (aPS/PT) detectable in sera of some patients with antiphospholipid syndrome (APS) have been shown to correlate with thrombosis. However, associations of aPS/PT antibodies with APS related disorders remain unclear.

Aim

To evaluate whether there are any associations between aPS/PT antibodies and Raynaud phenomenon, migraine and/or valvular lesions in primary thrombotic APS (PAPS).

Methods

We enrolled 67 consecutive patients (56 women) with thrombotic PAPS (VTE in 80.6%), aged 46.2 ± 13.5 years. The exclusion criteria were: acute coronary syndromes or stroke within preceding 6 months, cancer, severe comorbidities and pregnancy. The IgG and IgM aPS/PT antibodies were determined by ELISA with the cut-off of 30 units. We recorded Raynaud phenomenon, migraine and valvular lesions.

Results

Positive IgM or/and IgG aPS/PT antibodies were observed in 29 patients (43.3%), with a higher prevalence of IgM antibodies ( n = 27, 40.3%) compared with IgG isotype ( n = 12, 17.9%, p = 0.014). aPS/PT antibodies were observed most commonly in patients with triple aPL ( n = 12, 85.7%) compared with those with double ( n = 5, 35.7%) or single aPL antibodies (n = 12, 30.8%, p = 0.03), with no association with demographics, the ANA titre, the type of thrombotic events or medications. Raynaud phenomenon, migraine and valvular lesions were observed in 15% ( n = 10), 30% ( n = 20) and 18% ( n = 12) of the patients, respectively. Raynaud phenomenon and migraine, but not valvular lesions, were markedly more frequent in PAPS patients presenting with positive aPS/PT antibodies ( n = 10, 34.5% vs. n = 0, 0%; p = 0.0001).

Conclusions

In PAPS patients aPS/PT antibodies are related to the occurrence of both Raynaud phenomenon and migraine.

Alternative pathway activation due to low level of complement factor H in primary antiphospholipid syndrome

INTRODUCTION

Although complement activation has been proposed as a possible thrombophilic mechanism in antiphospholipid syndrome (APS), the origin of complement activation in APS remains unclear. Here, we focused on complement regulatory factors (CRF), which control the complement system to prevent damage to host tissue. We evaluated the function of two major CRF, membrane cofactor protein (MCP) and factor H (FH), in APS patients.

MATERIALS AND METHODS

In this study, we analyzed preserved serum samples from 27 patients with primary APS (PAPS), 20 with APS complicated with SLE (APS + SLE), 24 with SLE (SLE), and 25 with other connective tissue diseases (Other CTD). Serum MCP and FH levels were tested by ELISA. Autoantibodies against FH were determined by both ELISA and western-blotting.

RESULTS

Serum complement levels of PAPS were lower than those of other CTD (median C3: 82 vs 112 mg/dL, p < 0.01, C4: 15 vs 22 mg/dL, p < 0.05). Serum MCP levels did not significantly differ among the groups. Serum FH levels were significantly lower in PAPS patients compared with SLE or other CTD (median 204, 1275, and 1220 μg/mL, respectively, p < 0.01). In PAPS patients, serum FH levels were positively correlated with serum C3 levels (p < 0.01, R = 0.55), but no correlation was found with serum C4 levels (p = 0.22, R = 0.33). Autoantibodies against FH were not detected in any of our patients.

CONCLUSIONS

Activation of the alternative complement pathway due to low level of FH is one of the possible thrombophilic mechanisms in PAPS.

Diagnosing antiphospholipid syndrome: 'extra-criteria' manifestations and technical advances

First described in the early 1980s, antiphospholipid syndrome (APS) is a unique form of acquired autoimmune thrombophilia in which patients present with clinical features of recurrent thrombosis and pregnancy morbidity and persistently test positive for the presence of antiphospholipid antibodies (aPL). At least one clinical (vascular thrombosis or pregnancy morbidity) and one lab-based (positive test result for lupus anticoagulant, anticardiolipin antibodies and/or anti-β2-glycoprotein 1 antibodies) criterion have to be met for a patient to be classified as having APS. However, the clinical spectrum of APS encompasses additional manifestations that can affect many organs and cannot be explained exclusively by patients being in a prothrombotic state; clinical manifestations not listed in the classification criteria (known as extra-criteria manifestations) include neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease. Increasingly, research interest has focused on the development of novel assays that might be more specific for APS than the current aPL tests. This Review focuses on the current classification criteria for APS, presenting the role of extra-criteria manifestations and lab-based tests. Diagnostic approaches to difficult cases, including so-called seronegative APS, are also discussed.

Establishment of a rat model of thrombosis induced by intravenous injection of anti-phosphatidylserine-prothrombin complex antibody

Objective

Recent studies have suggested that aPS-PT antibody is one of the most relevant autoantibodies to APS. This study aimed to demonstrate the pathogenicity of aPS-PT antibody in vivo .

Methods

At first, cultured rat vascular endothelial cells (RECs) were exposed to calf thymus-derived histones. Two hours later, lactate dehydrogenase release from the RECs and expression of PS on the cell surface were assessed. Next, we administered an i.v. injection of calf thymus-derived histones into Wistar rats (12.5 µg/g weight of 8-week-old female rats), and 2 h later they were given an i.v. injection of aPS-PT mAb (1.25 mg/g weight, n = 6) or an equal dose of rat IgM as controls (n = 5). Three days later, histological examination was conducted.

Results

Calf thymus-derived histones (>12.5 µg/ml) could injure RECs in vitro . Simultaneously, annexin V could bind to the RECs; thereby, this result indicated that cell-free histone exposure of vascular endothelial cells induced cell surface expression of PS, which is naturally present inside the plasma membrane. Thrombosis developed with higher frequency in the rats given an i.v. injection of aPS-PT mAb than in controls.

Conclusion

We established a rat model of thrombosis induced by i.v. injection of aPS-PT mAb.

Recent advances in understanding antiphospholipid syndrome

Antiphospholipid syndrome (APS), also known as Hughes Syndrome, is a systemic autoimmune disease characterized by thrombosis and/or pregnancy morbidity in the presence of persistently positive antiphospholipid antibodies. A patient with APS must meet at least one of two clinical criteria (vascular thrombosis or complications of pregnancy) and at least one of two laboratory criteria including the persistent presence of lupus anticoagulant (LA), anticardiolipin antibodies (aCL), and/or anti-b2 glycoprotein I (anti-b2GPI) antibodies of IgG or IgM isotype at medium to high titres in patient’s plasma. However, several other autoantibodies targeting other coagulation cascade proteins (i.e. prothrombin) or their complex with phospholipids (i.e. phosphatidylserine/prothrombin complex), or to some domains of β2GPI, have been proposed to be also relevant to APS. In fact, the value of testing for new aPL specificities in the identification of APS in thrombosis and/or pregnancy morbidity patients is currently being investigated.

Ribophorin II is involved in the tissue factor expression mediated by phosphatidylserine-dependent antiprothrombin antibody on monocytes

OBJECTIVE

Phosphatidylserine-dependent, also called aPS-PT, recognizes the phosphatidylserine-prothrombin complex, which is associated with APS. We have previously reported that aPS-PT induces tissue factor (TF) expression on monocytes through the p38 mitogen-activated protein kinase pathway. However, the cell surface interaction between prothrombin and aPS-PT, which is involved in the activation of cell-signalling pathways, has remained unknown. The objective of this study was to identify membrane proteins involved in the binding of prothrombin and aPS-PT to monocyte surfaces as well as the induction of TF expression.

METHODS

RAW264.7 cells with FLAG-tagged prothrombin were incubated and separated using affinity chromatography with anti-FLAG antibody-conjugated Sepharose beads. Immunopurified proteins were then analysed by an online nano-liquid chromatography-tandem mass spectrometry. The binding between prothrombin and the identified protein, ribophorin II (RPN2), was analysed by ELISA and surface plasmon resonance. To elucidate the role of RPN2 in TF expression, the TF mRNA level in RAW264.7 cells treated with RPN2 small interfering RNA was determined by quantitative real-time PCR (qPCR).

RESULTS

RPN2 was identified as a candidate molecule involved in the binding of prothrombin to the cell surface. The binding between prothrombin and RPN2 was confirmed by ELISA and surface plasmon resonance. RAW264.7 cells treated with RPN2 small interfering RNA showed significant reduction of the TF expression mediated by prothrombin and a mouse monoclonal aPS-PT.

CONCLUSION

We identified that RPN2 is one of the prothrombin-binding proteins on monocyte surfaces, suggesting that RPN2 is involved in the pathophysiology of thrombosis in patients with APS.