scholarly journals The role of post-translational modifications by ubiquitin/ISG15 tags in exposed proteins during NETosis: Immunogenic or tolerogenic signaling process in Systemic Lupus Erythematosus?

2020 ◽  
Author(s):  
Daniel Alberto Carrillo-Vázquez ◽  
Eduardo Jardón-Valadez. ◽  
Jiram Torres-Ruiz ◽  
Guillermo Juárez-Vega ◽  
José Luis Maravillas-Montero ◽  
...  

Abstract Background: Neutrophil extracellular traps (NETs) from patients with Systemic Lupus Erythematosus (SLE) are characterized by lower ubiquitylation and myeloperoxidase (MPO) as a substrate. The structural and functional effect of such modification and if there are additional post-translational modifications (PTMs) are unknown.Methods: To assess the expression and functional role of PTMs in NETs of patients with SLE; reactivation, proliferation and cytokine production was evaluated by flow cytometry using co-cultures with dendritic cells (DC) and CD4+ from SLE patients and healthy controls. The impact of ubiquitylation on MPO was assessed by molecular dynamics. The expression of ISG15 in NETs was evaluated by immunofluorescence and Western Blot.Results: Fifteen patients with SLE and 10 healthy controls were included. In the co-cultures of CD4+ lymphocytes with DC stimulated with ubiquitylated MPO or recombinant MPO, a higher expression of IFNγ and IL17A was found in CD4+ from SLE patients (p < 0.05). Furthermore, with DC stimulated with ubiquitylated MPO a trend towards increased expression of CD25 and Ki67 was found in lupus CD4+ lymphocytes, while the opposite was documented in controls (p < 0.05). Through molecular dynamics we found the K129-K488-K505 residues of MPO as susceptible to ubiquitylation. Ubiquitylation affects the hydration status of the HEME group depending on the residue to which it is conjugated. R239 was found near by the HEME group when the ubiquitin was in K488-K505. In addition, we found greater expression of ISG15 in the SLE NETs vs controls (p < 0.05), colocalization with H2B (r = 0.78) only in SLE samples and increased production of IFNγ in PBMCs stimulated with lupus NETs compared to healthy controls NETs.Conclusion: The ubiquitylated MPO has a differential effect on the induction of reactivation and proliferation of CD4+ lymphocytes in patients with SLE, which may be related to structural changes by ubiquitylation at the catalytic site of MPO. Besides a lower ubiquitylation pattern, NETs of patients with SLE are characterized by the expression of H2B conjugated with ISG15, and the induction of IFNγ by Th1 cells.

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Daniel Alberto Carrillo-Vázquez ◽  
Eduardo Jardón-Valadez ◽  
Jiram Torres-Ruiz ◽  
Guillermo Juárez-Vega ◽  
José Luis Maravillas-Montero ◽  
...  

Abstract Background Neutrophil extracellular traps (NETs) from patients with systemic lupus erythematosus (SLE) are characterized by lower ubiquitylation and myeloperoxidase (MPO) as a substrate. The structural and functional effect of such modification and if there are additional post-translational modifications (PTMs) are unknown. Methods To assess the expression and functional role of PTMs in NETs of patients with SLE; reactivation, proliferation and cytokine production was evaluated by flow cytometry using co-cultures with dendritic cells (DC) and CD4+ from SLE patients and healthy controls. The impact of ubiquitylation on MPO was assessed by molecular dynamics. The expression of ISG15 in NETs was evaluated by immunofluorescence and Western Blot. Results Fifteen patients with SLE and ten healthy controls were included. In the co-cultures of CD4+ lymphocytes with DC stimulated with ubiquitylated MPO or recombinant MPO, a higher expression of IFNγ and IL-17A was found in CD4+ from SLE patients (p < 0.05). Furthermore, with DC stimulated with ubiquitylated MPO a trend towards increased expression of CD25 and Ki67 was found in lupus CD4+ lymphocytes, while the opposite was documented in controls (p < 0.05). Through molecular dynamics we found the K129-K488-K505 residues of MPO as susceptible to ubiquitylation. Ubiquitylation affects the hydration status of the HEME group depending on the residue to which it is conjugated. R239 was found near by the HEME group when the ubiquitin was in K488-K505. In addition, we found greater expression of ISG15 in the SLE NETs vs controls (p < 0.05), colocalization with H2B (r = 0.81) only in SLE samples and increased production of IFNγ in PBMCs stimulated with lupus NETs compared to healthy controls NETs. Conclusion The ubiquitylated MPO has a differential effect on the induction of reactivation of CD4+ lymphocytes in patients with SLE, which may be related to structural changes by ubiquitylation at the catalytic site of MPO. Besides a lower ubiquitylation pattern, NETs of patients with SLE are characterized by the expression of ISG15, and the induction of IFNγ by Th1 cells.


2020 ◽  
Author(s):  
Daniel Alberto Carrillo-Vázquez ◽  
Eduardo Jardón-Valadez. ◽  
Jiram Torres-Ruiz ◽  
Guillermo Juárez-Vega ◽  
José Luis Maravillas-Montero ◽  
...  

Abstract Background: Neutrophil extracellular traps (NETs) from patients with Systemic Lupus Erythematosus (SLE) are characterized by lower ubiquitylation and myeloperoxidase (MPO) as a substrate. The structural and functional effect of such modification and if there are additional post-translational modifications (PTMs) are unknown. Methods: To assess the expression and functional role of PTMs in NETs of patients with SLE; reactivation, proliferation and cytokine production was evaluated by flow cytometry using co-cultures with dendritic cells (DC) and CD4+ from SLE patients and healthy controls. The impact of ubiquitylation on MPO was assessed by molecular dynamics. The expression of ISG15 in NETs was evaluated by immunofluorescence and Western Blot. Results: Fifteen patients with SLE and 10 healthy controls were included. In the co-cultures of CD4+ lymphocytes with DC stimulated with ubiquitylated MPO or recombinant MPO, a higher expression of IFNγ and IL17A was found in CD4+ from SLE patients (p<0.05). Furthermore, with DC stimulated with ubiquitylated MPO a trend towards increased expression of CD25 and Ki67 was found in lupus CD4+ lymphocytes, while the opposite was documented in controls (p<0.05). Through molecular dynamics we found the K129-K488-K505 residues of MPO as susceptible to ubiquitylation. Ubiquitylation affects the hydration status of the HEME group depending on the residue to which it is conjugated. R239 was found near by the HEME group when the ubiquitin was in K488-K505. In addition, we found greater expression of ISG15 in the SLE NETs vs controls (p<0.05), colocalization with H2B (r=0.78) only in SLE samples and increased production of IFNγ in PBMCs stimulated with lupus NETs compared to healthy controls NETs. Conclusion: The ubiquitylated MPO has a differential effect on the induction of reactivation of CD4+ lymphocytes in patients with SLE, which may be related to structural changes by ubiquitylation at the catalytic site of MPO. Besides a lower ubiquitylation pattern, NETs of patients with SLE are characterized by the expression of ISG15, and the induction of IFNγ by Th1 cells.


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
David M Patrick ◽  
Nestor de la Visitacion ◽  
Michelle J Ormseth ◽  
Charles Stein ◽  
Sean S Davies ◽  
...  

Essential hypertension and systemic lupus erythematosus (SLE) are devastating conditions that disproportionately affect women. SLE has heterogeneous manifestations and treatment is limited to the use of non-specific global immunosuppression. Importantly, there is an increased prevalence of hypertension in women with SLE compared to healthy controls. Isolevuglandins (IsoLGs) are oxidation products of fatty acids that form as a result of reactive oxygen species. These molecules adduct covalently to lysine residues of proteins. Adducted proteins are then presented as autoantigens to T-cells resulting in immune cell activation. Previous studies have shown an essential role of IsoLGs in immune cell activation and the development of hypertension in animal models. We hypothesize that isoLGs are important for the development of hypertension and systemic immune activation in SLE. We first examined isoLG adduct accumulation within monocytes of human subjects with SLE compared to healthy controls. By flow cytometry, we found marked accumulation of isoLG adducts within CD14 + monocytes (34.2% ± 12.4% vs 3.81% ± 2.1% of CD14 + , N = 10-11, P <0.05). We confirmed this increase in isoLG adducts by mass spectrometry. To determine a causative role of isoLG adducts in immune activation and hypertension in SLE, we employed the B6.SLE123 and NZBWF1 mouse models of SLE. Animals were treated with the isoLG scavenger 2-hydroxybenzylamine (2-HOBA) or vehicle beginning at 7 weeks and were sacrificed at 32 weeks of age. C57BL/6 and NZW were used as controls. Importantly, treatment with 2-HOBA attenuated blood pressure in both mouse models (systolic BP 136.2 ± 5.6 mmHg for B6.SLE123 vs 120.9 ± 4.46 mmHg for B6.SLE123 +2HOBA; 164.7 ± 24.4 mmHg for NZBWF1 vs 136.9 ± 14.9 mmHg for NZBWF1 +2HOBA, N = 6-8, P < 0.05). Moreover, treatment with 2-HOBA reduced albuminuria and renal injury in the B6.SLE123 model (albumin/creatinine ratio 33.8 ± 2.0 x 10 -2 μg/mg for B6.SLE123 vs 5.5 ± 0.9 x 10 -2 μg/mg for B6.SLE123 +2HOBA, N = 7-9, P < 0.05). Finally, immune cell accumulation in primary and secondary lymphoid organs is significantly attenuated by 2-HOBA. These studies suggest a critical role of isoLG adduct accumulation in both systemic immune activation and hypertension in SLE.


Lupus ◽  
2011 ◽  
Vol 20 (14) ◽  
pp. 1494-1500 ◽  
Author(s):  
Z Rezaieyazdi ◽  
M Sahebari ◽  
MR Hatef ◽  
B Abbasi ◽  
H Rafatpanah ◽  
...  

The role of C-reactive protein (CRP) in systemic lupus erythematosus (SLE) as an inflammatory marker is still controversial. Recently, more sensitive methods, such as high sensitive CRP (hs-CRP) have been used to detect micro-inflammation. The role of hs-CRP in lupus flare has not been documented well. We conducted this study to examine the correlation between hs-CRP serum concentrations and disease activity in lupus. Ninety-two SLE patients and 49 healthy controls contributed to our study. Most confounding factors influencing the hs-CRP values were excluded. Disease activity was estimated using the SLE Disease Activity Index (SLEDAI-2K). hs-CRP values were determined using an enzyme-linked immunosorbent assay (ELISA) kit. Serum values of hs-CRP were significantly higher ( p < 0.001, z = 3.29) in patients compared with healthy controls. The cutoff point for hs-CRP between patients and controls was 0.93 mg/L (Youden’s Index = 0.39). There was no correlation between hs-CRP serum levels and disease activity. Furthermore, hs-CRP values did not correlate with any of the laboratory parameters, except for C3 ( p = 0.003, rs = −0.2) and C4 ( p = 0.02, rs = −0.1). Although hs-CRP serum levels were significantly higher in lupus patients compared with healthy controls, it seems that this marker is not a good indicator for disease activity.


2020 ◽  
Author(s):  
Yanxia Zhan ◽  
Boting Wu ◽  
Chanjuan liu ◽  
Luya Cheng ◽  
Lili Ji ◽  
...  

Abstract Background : Primary immune thrombocytopenia (ITP) is an autoimmune-mediated disorder characterized by decreased platelet count. Systemic lupus erythematosus (SLE) is also an autoimmune disease which thrombocytopenia is a common hematologic manifestation. Interleukin (IL)-1 family cytokines are major proinflammatory and immunoregulatory mediators. This study aimed to investigate the role of IL-1 cytokines in patients with ITP and SLE and the potential pathophysiologic mechanism to differentiate SLE-associated thrombocytopenia (SLE-TP) from ITP. Methods : Multiplex cytokine assay and real-time polymerase chain reaction (RT-PCR) were used to measure the IL-1 cytokines in 17 newly diagnosed ITP patients, 17 SLE-TP patients, 19 SLE patients without thrombocytopenia (SLE-NTP) and 10 healthy controls. Results : The serum levels of IL-1β, IL-18, IL-36α, IL-36β, IL-36γ and IL-33 were decreased significantly in ITP patients as compared with SLE-TP, SLE-NTP patients and healthy controls ( p <0.05). There was no significantly difference in the serum level of IL-37 between ITP and SLE-TP patients, however, there is a positive correlation between platelet count with IL-37 level in ITP patients. Our data suggested that serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ, IL-33 and IL-37 were involved in the pathogenesis of ITP. Conclusions : Serum IL-1β, IL-18, IL-36α, IL-36β, IL-36γ and IL-33 could be considered biomarkers to differentiate SLE-TP from ITP patients.


2020 ◽  
Vol 14 (12) ◽  
pp. 1109-1119
Author(s):  
Hemant J Vira ◽  
Vandana D Pradhan ◽  
Vinod D Umare ◽  
Ajay K Chaudhary ◽  
Anjali G Rajadhyksha ◽  
...  

Aim: To investigate the possible association between MMP-2 (−1575 G/A, −1306 C/T) and its inhibitor TIMP-2 (−418 G/C) functional polymorphisms with development of severity in systemic lupus erythematosus (SLE) patients. Materials & methods: 150 SLE patients and matched healthy controls were recruited. Polymorphisms were detected by PCR-RFLP and serum levels by ELISA. Results: Mean MMP-2 and TIMP-2 serum level and mRNA expression were significantly increased in SLE cases as compared with controls (p < 0.0001). The concomitant presence of both MMP-2 1575A and its inhibitor TIMP-2 418C alleles synergistically increased the risk of SLE by 3.25-fold (CI: 1.44–7.34, p = 0.003). Conclusion: MMP-2, TIMP-2 and MMP-2/TIMP-2 ratios may act as biomarkers for susceptibility to SLE.


2014 ◽  
Vol 38 (6) ◽  
Author(s):  
Mohammad Najafi ◽  
Freshteh Parto ◽  
Parisa Mohammadi ◽  
Mohammad Shabani

AbstractSystemic lupus erythematosus (SLE) is an autoimmune disease with different clinical manifestations. The inflammatory and oxidative modification reactions are the most important events associated with cardiovascular complications of SLE patients. The aim of this study was to investigate the nitric oxide (NO) and the oxidized low-density lipoprotein (Ox-LDL) levels in order to explain the role of oxidized particles in development of clinical manifestations.A total of 80 subjects, SLE patients (n=40) and healthy controls (n=40), were recruited and matched regarding to age, gender, and body mass index (BMI). The biochemical parameters were measured using routine laboratory methods. The plasma Ox-LDL and NO levels were assayed with ELISA and colorimetric techniques, respectively.The plasma NO level was significantly high in SLE patients (33.03±18.09 μmol/mL) in comparison to healthy controls (15.25±11.54 μmol/mL). In contrast, the total and normalized (Ox-LDL/LDL) plasma Ox-LDL values were low in SLE patients (p=0.2 and p<0.05, respectively). A linear negative correlation was also observed between the plasma Ox-LDL and NO levels (r=0.25, p<0.05). Multiple logistic regression analysis showed the critical role of NO on Ox-LDL level. Moreover, the disease activity and medications did not relate to the plasma Ox-LDL level (p>0.5).The results showed that the excess NO prevents the oxidation of LDL particles so that the inflammatory events in comparison to oxidative modifications may be most involved in clinical complications of SLE patients.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Alimohammad Fatemi ◽  
Razieh Alipour ◽  
Hossein Khanahmad ◽  
Fereshteh Alsahebfosul ◽  
Alireza Andalib ◽  
...  

Abstract Background NET (neutrophil extracellular trap) has been shown to directly influence inflammation; in SLE (systemic lupus erythematosus), it is reportedly a plausible cause for the broken self-tolerance that contributes to this pathology. Meanwhile, the role of NET is not easily explicable, and there is a serious discrepancy in the role of NET in SLE pathology and generally inflammation; in particular, the interactions of neutrophils with NET have been rarely inspected. This study evaluates the effect of NET on neutrophils in the context of SLE. The neutrophils were incubated by the collected NET (from SLE patients and healthy controls) and their expression of an activation marker, viability and oxidative burst ability were measured. Results The level of cell mortality, CD11b expression and the oxidative burst capacity were elevated in NET-treated neutrophils. Also, the elevation caused by the SLE NET was higher than that produced by the healthy NET. Conclusion The decreased neutrophil viability was not due to the increase in apoptosis; rather, it was because of the augmentation of other inflammatory cell-death modes. The upregulation of CD11b implies that NET causes neutrophils to more actively contribute to inflammation. The increased oxidative burst capacity of neutrophils can play a double role in inflammation. Overall, the effects induced by NET on neutrophils help prolong inflammation; accordingly, the NET collected from SLE patients is stronger than the NET from healthy individuals.


2021 ◽  
Vol 8 ◽  
Author(s):  
Anika Wiechmann ◽  
Benjamin Wilde ◽  
Bartosz Tyczynski ◽  
Kerstin Amann ◽  
Wayel H. Abdulahad ◽  
...  

Cytotoxic CD8+ T-cells play a pivotal role in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to investigate the role of CD107a (LAMP-1) on cytotoxic CD8+ T-cells in SLE-patients in particular with lupus nephritis. Peripheral blood of SLE-patients (n = 31) and healthy controls (n = 21) was analyzed for the expression of CD314 and CD107a by flow cytometry. Kidney biopsies of lupus nephritis patients were investigated for the presence of CD8+ and C107a+ cells by immunohistochemistry and immunofluorescence staining. The percentages of CD107a+ on CD8+ T-cells were significantly decreased in SLE-patients as compared to healthy controls (40.2 ± 18.5% vs. 47.9 ± 15.0%, p = 0.02). This was even more significant in SLE-patients with inactive disease. There was a significant correlation between the percentages of CD107a+CD8+ T-cells and SLEDAI. The evaluation of lupus nephritis biopsies showed a significant number of CD107a+CD8+ T-cells mainly located in the peritubular infiltrates. The intrarenal expression of CD107a+ was significantly correlated with proteinuria. These results demonstrate that CD8+ T-cells of patients with systemic lupus erythematosus have an altered expression of CD107a which seems to be associated with disease activity. The proof of intrarenal CD107a+CD8+ suggests a role in the pathogenesis of lupus nephritis.


2017 ◽  
Vol 44 (1) ◽  
pp. 412-422 ◽  
Author(s):  
Ning An ◽  
Yanwen Chen ◽  
Chao Wang ◽  
Chen Yang ◽  
Zhi-hong Wu ◽  
...  

Background: Imbalanced cellular immunity is critical to the pathogenesis of systemic lupus erythematosus (SLE). Recently, autophagy has emerged as a key homeostatic mechanism in T lymphocytes. This study was conducted to explore the impact of autophagy on the Th17/ regulatory T (Treg) immune imbalance in SLE. Methods: Peripheral Th17 and Treg cells from newly diagnosed patients with SLE and healthy controls were detected by flow cytometry. Additionally, the effects of chloroquine (CQ) autophagic inhibition on the Th17/Treg immune response were investigated in vitro. In addition, hydroxychloroquine (HCQ) treatment of the Th17/Treg immune response and the disease progression of lupus MRL/lpr mice were studied in vivo. Results: Compared with healthy controls, both peripheral Th17 and Treg cells of patients with SLE exhibited activated autophagy, resulting in a heightened Th17 proinflammatory response and diminished Treg immunosuppression. Furthermore, in vitro experiments indicated that CQ autophagic inhibition effectively rebalanced the Th17/Treg immune responses in patients with SLE. In vivo studies of MRL/lpr mice similarly confirmed that HCQ treatment decisively inhibited the autophagy of Th17/Treg cellular subsets, restoring the immune balance, lowering the serum levels of inflammatory cytokines and autoantibodies, and improving renal histopathology. Conclusion: Activated autophagy contributed to the Th17/Treg immune imbalance in SLE, and chloroquine autophagic inhibition rebalanced Th17/ Treg-mediated immunity and ameliorated SLE.


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