Circulating Angiogenic T Cells Are Increased in Lupus Nephritis Patients

The Pathogenic Role of Expanded CD8⁺CD28null Angiogenic T Cells in ANCA-Associated Vasculitis

Objectives: Angiogenic T cells (Tang) are crucial in promoting angiogenesis, with the loss of CD28 serving as a marker for highly differentiated and senescent T cells. This study aims to investigate the characteristics and potential roles of CD8+CD28null Tang in patients with ANCA-associated vasculitis (AAV). Methods: A cohort of AAV patients and matched healthy controls (HCs) were analyzed. Flow cytometry was used to assess the profiles of circulating CD8+CD28null Tang. In vitro functional assays were performed to evaluate the pathogenic properties of CD8+CD28null Tang. Results: CD8+CD28null Tang levels were significantly higher in the peripheral blood of AAV patients compared to HCs, and their levels were further increased in AAV patients with MPO⁺, p-ANCA⁺, or interstitial lung disease compared to their respective control groups. Additionally, there was a positive correlation between both the percentage and absolute count of CD8+CD28null Tang and the Birmingham Vasculitis Activity Score (BVAS). In patients with a good treatment response, both the percentage and absolute count of CD8+CD28null Tang were significantly reduced, and this reduction was positively correlated with the decrease in BVAS scores. In vitro studies revealed that CD8+CD28null Tang displayed enhanced chemotactic properties, induced apoptosis in human umbilical vein endothelial cells (HUVECs), and inhibited their proliferation, migration, and tube formation. Conclusions: AAV patients exhibit increased levels of circulating CD8+CD28null Tang, which can be reduced following effective treatment. Furthermore, CD8+CD28null Tang may contribute to the pathogenesis of AAV by promoting apoptosis and inhibiting the proliferation, migration, and tube formation of HUVECs.

The vascular endothelial growth factor as a candidate biomarker of systemic lupus erythematosus: a GRADE-assessed systematic review and meta-analysis

There is an ongoing search for novel biomarkers of endothelial damage, active disease, and organ dysfunction in systemic lupus erythematosus (SLE). We investigated the role of the vascular endothelial growth factor (VEGF) as a candidate biomarker by conducting a systematic review and meta-analysis of studies examining VEGF concentrations in SLE patients and healthy controls. We searched electronic databases (PubMed, Scopus, and Web of Science) from inception to 31 May 2024 (inclusion criteria: VEGF measurement in SLE patients and healthy controls and SLE patients with and without active disease or specific organ dysfunction in case-control studies, recruitment of adult participants, and availability of the full text in the English language; exclusion criteria: non-case-control studies, participants under 18 years, articles reporting duplicate or irrelevant data, and animal studies). We assessed the risk of bias and the certainty of evidence using the JBI Critical Appraisal Checklist and GRADE, respectively (PROSPERO registration number: CRD42024561636). Circulating VEGF concentrations were significantly higher in SLE patients than in controls (22 studies; standardised mean difference, SMD = 0.71, 95% CI 0.44 to 0.98, p < 0.001; low certainty of evidence). In SLE patients, VEGF concentrations were significantly higher in those with active disease (six studies; SMD = 1.10, 95% CI 0.27 to 1.92, p = 0.009; very low certainty of evidence) and lupus nephritis (four studies; SMD = 0.80, 95% CI 0.03 to 1.57, p = 0.042; very low certainty of evidence). Only one study reported VEGF concentrations in SLE patients with and without pulmonary arterial hypertension. The effect size of the differences in VEGF concentrations between SLE patients and controls was not associated with disease duration, use of glucocorticoids and immunosuppressors, biological matrix assessed, or analytical method used. However, it was significantly associated with the study's geographical location. The evidence was limited by the high but partially explainable heterogeneity and the presence of publication bias which was addressed with the "trim-and-fill" method (SLE presence), the high but partially explainable heterogeneity and lack of assessment of publication bias because of the limited study number (active disease), and the limited study number preventing the identification of sources of heterogeneity, sensitivity analysis, and assessment of publication bias (lupus nephritis). Our results highlight VEGF's potential role as a SLE biomarker and the need for further research, also given the aforementioned limitations, investigating VEGF concentrations in a wide range of SLE patient subgroups.

Immune mechanisms associated with cardiovascular disease in systemic lupus erythematosus: A path to potential biomarkers

Systemic lupus erythematosus (SLE) patients display an increased risk of cardiovascular disease (CVD). With the improved clinical management of other classical severe manifestation of the disease, CVD is becoming one of the most relevant complications of SLE, and it is an important factor causing morbidity and mortality. Several immune constituents have been shown to be involved in the pathogenesis of atherosclerosis and endothelial damage in SLE patients, including specific circulating cell populations, autoantibodies, and inflammatory mediators. In this review, we summarize the presentation of CVD in SLE and the role of the autoimmune responses present in SLE patients in the induction of atherogenesis, endothelial impairment and cardiac disease. Additionally, we discuss the utility of these immune mediators as early CVD biomarkers and targets for clinical intervention in SLE patients.

Endothelial function and endothelial progenitor cells in systemic lupus erythematosus

The observations that traditional cardiovascular disease (CVD) risk factors fail to fully account for the excessive cardiovascular mortality in patients with systemic lupus erythematosus (SLE) compared with the general population have prompted in-depth investigations of non-traditional, SLE-related risk factors that contribute to cardiovascular complications in patients with SLE. Of the various perturbations of vascular physiology, endothelial dysfunction, which is believed to occur in the earliest step of atherosclerosis, has been extensively investigated for its contribution to CVD risk in SLE. Endothelial progenitor cells (EPCs), which play a crucial part in vascular repair, neovascularization and maintenance of endothelial function, are quantitatively and functionally reduced in patients with SLE. Yet, the lack of a unified definition of EPCs, standardization of the quantity and functional assessment of EPCs as well as endothelial function measurement pose challenges to the translation of endothelial function measurements and EPC levels into prognostic markers for CVD in patients with SLE. This Review discusses factors that contribute to CVD in SLE, with particular focus on how endothelial function and EPCs are evaluated currently, and how EPCs are quantitatively and functionally altered in patients with SLE. Potential strategies for the use of endothelial function measurements and EPC quantification as prognostic markers of CVD in patients with SLE, and the limitations of their prognostication potential, are also discussed.

Angiogenic T Cells: Potential Biomarkers for the Early Diagnosis of Interstitial Lung Disease in Autoimmune Diseases?

(1) Background: We explored, for the first time, the contribution of angiogenic T cells (TAng) in interstitial lung disease associated to autoimmune disease (AD-ILD+) as potential biomarkers of the disease, evaluating their role in the underlying vasculopathy and lung fibrosis. Additionally, the relationship of TAng with clinical manifestations and cellular and molecular endothelial dysfunction-related biomarkers was assessed. (2) Methods: We included 57 AD-ILD+ patients (21 with rheumatoid arthritis (RA)-ILD+, 21 with systemic sclerosis (SSc)-ILD+ and 15 with other AD-ILD+) and three comparative groups: 45 AD-ILD− patients (25 RA-ILD− and 20 SSc-ILD−); 21 idiopathic pulmonary fibrosis (IPF) patients; 21 healthy controls (HC). TAng were considered as CD3+CD184+CD31+ by flow cytometry. (3) Results: A similar TAng frequency was found between AD-ILD+ and IPF, being in both cases lower than that observed in AD-ILD− and HC. A lower TAng frequency was associated with negative Scl-70 status and lower FEV1/FVC ratio in SSc-ILD+, as well as with men in RA-ILD+ and non-specific interstitial pneumonia radiological pattern in other AD-ILD+. No relationship between TAng and endothelial progenitor cells, endothelial cells and vascular endothelial growth factor gene expression and protein levels was disclosed. (4) Conclusions: Our findings suggest TAng as potential biomarkers for the early diagnosis of ILD in AD.

A review on the role of chemokines in the pathogenesis of systemic lupus erythematosus

Chemokines are a group of cytokines with low molecular weight that principally direct chemotaxis of target cells. They have prominent roles in the pathogenesis systemic lupus erythematosus (SLE) and related complications particularly lupus nephritis. These molecules not only induce autoimmune responses in the organs of patients, but also can amplify the induced inflammatory responses. Although chemokine family has at least 46 identified members, the role of a number of these molecules have been more clarified in SLE patients or animal models of this disorder. In the current paper, we review the role of CCL2, CCL3, CCL4, CCL11, CCL20, CXCL1, CXCL2, CXCL8, CXCL10, CXCL12 and CXCL13 in the pathogenesis of SLE.

IFN-I Mediates Dysfunction of Endothelial Progenitor Cells in Atherosclerosis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease including the cardiovascular system. Atherosclerosis is the most common cardiovascular complication of SLE and a significant risk factor for morbidity and mortality. Vascular damage/protection mechanism in SLE patients is out of balance, caused by the cascade reaction among oxidative stress, proinflammatory cytokines, Neutrophil Extracellular Traps, activation of B cells and autoantibodies and abnormal T cells. As a precursor cell repairing vascular endothelium, endothelial progenitor cells (EPCs) belong to the protective mechanism and show the reduced number and impaired function in SLE. However, the pathological mechanism of EPCs dysfunction in SLE remains ill-defined. This paper reviews the latest SLE epidemiology and pathogenesis, discusses the changes in the number and function of EPCs in SLE, expounds the role of EPCs in SLE atherosclerosis, and provides new guidance and theoretical basis for exploring novel targets for SLE treatment.

T Cells Subsets in the Immunopathology and Treatment of Sjogren's Syndrome

Sjogren´s syndrome (SS) is an autoimmune disease whose pathogenesis is characterized by an exacerbated T cell infiltration in exocrine glands, markedly associated to the inflammatory and detrimental features as well as the disease progression. Several helper T cell subsets sequentially converge at different stages of the ailment, becoming involved in specific pathologic roles. Initially, their activated phenotype endows them with high migratory properties and increased pro-inflammatory cytokine secretion in target tissues. Later, the accumulation of immunomodulatory T cells-derived factors, such as IL-17, IFN-γ, or IL-21, preserve the inflammatory environment. These effects favor strong B cell activation, instigating an extrafollicular antibody response in ectopic lymphoid structures mediated by T follicular helper cells (Tfh) and leading to disease progression. Additionally, the memory effector phenotype of CD8+ T cells present in SS patients suggests that the presence of auto-antigen restricted CD8+ T cells might trigger time-dependent and specific immune responses. Regarding the protective roles of traditional regulatory T cells (Treg), uncertain evidence shows decrease or invariable numbers of circulating and infiltrating cells. Nevertheless, an emerging Treg subset named follicular regulatory T cells (Tfr) seems to play a critical protective role owing to their deficiency that enhances SS development. In this review, the authors summarize the current knowledge of T cells subsets contribution to the SS immunopathology, focusing on the cellular and biomolecular properties allowing them to infiltrate and to harm target tissues, and that simultaneously make them key therapeutic targets for SS treatment.

Fractalkine mediates lymphocyte inflammation and tubulointerstitial lesions by modifying the Treg/Th17 balance in lupus-prone MRL/lpr mice

In this study, we first analyzed the expression level of fractalkine (FKN) in the serum of patients with lupus nephritis (LN) and the distribution of peripheral blood Treg cells, and explored FKN and Treg cells, systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K) correlation. Subsequently, we explored the specific role of FKN in tubule interstitial lesions (TILs) and regulatory T (Treg) cells/T helper (Th) 17 cell balance in lupus model mice. Treated with an anti-FKN antibody (aFKN), recombinant FKN (rFKN), or an isotype antibody (IgG) in MRL/MpJ-Faslpr/J and C57BL/6 mice, and then detected TIL level and forkhead box p3 (Foxp3), IL-10, IL-17 and IL-6 expression levels in the kidney and spleen in the proportion of Treg and Th17 cells. Finally, then use aFKN, rFKN, or IgG to intervene in polarized Tregs with IL-6, TGF-β, IL-23, anti-interferon, and Th17 cells with anti-IL-4 after transforming to transform growth factor (TGF)-β and interleukin (IL)-2 in isolated mouse spleen lymphocytes. The results showed that the expression level of FKN was positively correlated with SLEDAI-2K and negatively correlated with the distribution of Treg cells. After treatment with aFKN in lupus model mice, kidney damage was delayed, TIL formation was reduced, Foxp3 and IL-10 levels were up-regulated, IL-17 and IL-6 levels were down-regulated in renal tissues, Th17 cell subsets and Treg cell subsets were reduced The increase is in the spleen, and rFKN treatment has the opposite effect in mouse. In addition, after interfering with polarized cells by aFKN, it was found that IL-17 and IL-6 expression levels were down-regulated in Th17 cells, Foxp3 and IL-10 levels in Tregs were up-regulated, and rFKN treatment had the opposite effect in vitro. These results indicate that FKN participates in and promotes SLE target organ damage including: secretion of inflammatory factors and renal TIL, and most importantly, these effects might have been due to modification of the Treg/Th17 cell balance.

Angiogenic T cells are decreased in people with type 2 diabetes mellitus and recruited by the dipeptidyl peptidase-4 inhibitor Linagliptin: A subanalysis from a randomized, placebo-controlled trial (RELEASE study)

Angiogenic T (Tang) cells are mediators of vascular repair, and are characterized by surface expression of CXCR4. This receptor for stromal cell-derived factor-1α (SDF-1α) is cleaved by dipeptidyl peptidase-4 (DPP-4). Tang cell levels were investigated in people with type 2 diabetes mellitus (T2DM) compared with matched healthy controls and after treatment with the DPP-4 inhibitor Linagliptin. People with T2DM were randomized to 5 mg/day Linagliptin (n = 20) or placebo (n = 21) for 26 weeks. Tang cell frequency was identified in peripheral blood mononuclear cells (CD3⁺ CD31⁺ CXCR4⁺ ) and levels of endothelial progenitor cells (EPCs) (CD34⁺ CD133⁺ KDR⁺ ) were also assessed in whole blood. Circulating Tang cell levels were significantly lower in people with T2DM compared with the healthy control group. SDF-1α levels increased significantly in Linagliptin-treated people with T2DM compared to placebo, and a trend was observed in change of Tang cell levels, while EPC count did not change. In conclusion, circulating Tang cell levels were considerably lower in people with T2DM, while a trend was observed in recruitment of Tang cells after 26 weeks of treatment with Linagliptin. These data suggest that DPP-4 inhibitors may potentially exert beneficial effects on bone marrow-driven vascular repair.

The risk of circulating angiogenic T cells and subsets in patients with systemic sclerosis

To ascertain the number and percentage of angiogenic T (Tang) cell subsets by flow cytometry in systemic sclerosis (SSc), and their relation with specific clinical features. Thirty SSc patients and 15 healthy controls (HCs) were included. Luminex was performed to analyze the levels of interleukin (IL)-17A, vascular endothelial growth factor (VEGF), tumor necrosis factor-α, and vascular cell adhesion molecule (VCAM). The ratio of circulating CD3 + CD31 + CXCR4 + T (CD3 + Tang) cells and CD8+ CD31 + CXCR4 + T (CD8+ Tang) cells in SSc patients was enlarger than in HCs, while CD4 + CD31 + CXCR4 + T cells (CD4 + Tang) exhibited no difference between SSc patients and HCs. The number and percentage of Tang cells were higher in SSc patients with pulmonary artery hypertension (PAH) than in non-PAH SSc patients and HCs. The ratios of Tang cell subsets in nucleolar pattern-positive SSc patients were markedly raised as compared with their negative ones and HCs. Additionally, the percentage of circulating CD3 + Tang cells was positively associated with VEGF serum levels in SSc patients. Meanwhile, the rate of CD8+ tang cells might have been emphatically corresponded to VEGF and VCAM serum levels in SSc patients. These results imply that the increase in Tang cells in peripheral blood are associated with immunoregulatory disturbances in SSc patients.

MicroRNA-145 Involves in the Pathogenesis of Renal Vascular Lesions and May Become a Potential Therapeutic Target in Patients with Juvenile Lupus Nephritis

AIMS

The current study was conducted with the central objective of investigating the expression of microRNA-145 (miR-145) in renal vascular lesions (RVLs) in juvenile lupus nephritis (JLN) and its possible mechanism.

METHODS

The clinical data of 49 JLN patients confirmed by renal biopsy were collected and followed by grouping according to the RVLs score after hematoxylin-eosin staining: mild, moderate, and severe groups. In situ hybridization was used to detect the expression of miR-145 in renal vessels which was then being compared among different RVLs groups. Up-LV-miR-145 and LV-miR-NC lentiviral vectors were constructed and transfected into human vascular smooth muscle cells (HVSMCs), respectively. After HVSMCs were treated with 10.0 µg/L platelet-derived growth factor (PDGF)-BB for 24 h, the proliferation, migration, and apoptosis of endothelial cells were detected by MTT, Transwell assay, and flow cytometry, respectively. Western blot was used to detect expression of alpha-smooth muscle actin (α-SM-actin) and osteopontin (OPN).

RESULTS

The expression of miR-145 in renal vascular cells was statistically significant. The higher the inner membrane ratio, the lesser the miR-145 expression. After treatment with PDGF-BB, expression of miR-145 in HVSMCs decreased, proliferation and migration ability enhanced, apoptosis decreased, α-SM-actin decreased, and OPN increased. The proliferation and migration ability of HVSMCs in the LV-miR-145 group suppressed, apoptosis enhanced, α-SM-actin increased, and OPN decreased.

CONCLUSIONS

Our study revealed that miR-145 expression decreased with the increase of vascular damage. miR-145 can inhibit proliferation, migration, and differentiation phenotypic transformation of HVSMCs induced by PDGF-BB. miR-145 may be involved in the pathogenesis of RVLs and may be a new target for treatment of RVLs in lupus nephritis.