Dysfunction In Systemic Lupus Erythematosus Research Articles

CMPK2 Promotes CD4+ T Cell Activation and Apoptosis through Modulation of Mitochondrial Dysfunction in Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterized by abnormal autoantibodies, immune complex deposition, and tissue inflammation. Despite extensive research, the exact etiology and progression of SLE remain elusive. Cytidine/uridine monophosphate kinase 2 (CMPK2), a mitochondrial nucleoside monophosphate kinase, has garnered attention for its potential involvement in the development of various diseases, including SLE, where it has been observed to be dysregulated in affected individuals. However, the specific involvement of CMPK2 in the pathogenesis of SLE remains unclear. This study aims to clarify the expression level of CMPK2 in SLE CD4+ T cells and explore its impact on CD4+ T cells. The expression levels of the CMPK2 gene and the corresponding CMPK2 protein in CD4+ T cells of SLE patients were quantified using RT-qPCR and Western blot, respectively. Immunofluorescence and RT-qPCR were used to assess the mitochondrial function of SLE CD4+ T cells. Flow cytometry was used to assess CD4+ T cell activation and apoptosis levels. The impact of CMPK2 on CD4+ T cells was investigated by gene transfection experiment. We found that CMPK2 was significantly upregulated in SLE CD4+ T cells at both gene and protein levels. These cells demonstrated aberrant mitochondrial function, as evidenced by elevated mitochondrial reactive oxygen species (mtROS) levels, mitochondrial membrane potential, and mitochondrial DNA (mtDNA) copy number. Flow cytometry revealed a notable increase in both apoptosis and activation levels of CD4+ T cells in SLE patients. Gene transfection experiments showed that suppressing CMPK2 led to a significant improvement in these conditions. These findings suggest that CMPK2 may be involved in the pathogenesis of SLE by regulating mitochondrial dysfunction in CD4+ T cells and thus affecting CD4+ T cell activation and apoptosis. Our study may provide a new target for the treatment of SLE.

Mitochondrial Dysfunction in Systemic Lupus Erythematosus with a Focus on Lupus Nephritis.

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting mostly women of child-bearing age. Immune dysfunction in SLE results from disrupted apoptosis which lead to an unregulated interferon (IFN) stimulation and the production of autoantibodies, leading to immune complex formation, complement activation, and organ damage. Lupus nephritis (LN) is a common and severe complication of SLE, impacting approximately 30% to 40% of SLE patients. Recent studies have demonstrated an alteration in mitochondrial homeostasis in SLE patients. Mitochondrial dysfunction contributes significantly to SLE pathogenesis by enhancing type 1 IFN production through various pathways involving neutrophils, platelets, and T cells. Defective mitophagy, the process of clearing damaged mitochondria, exacerbates this cycle, leading to increased immune dysregulation. In this review, we aim to detail the physiopathological link between mitochondrial dysfunction and disease activity in SLE. Additionally, we will explore the potential role of mitochondria as biomarkers and therapeutic targets in SLE, with a specific focus on LN. In LN, mitochondrial abnormalities are observed in renal cells, correlating with disease progression and renal fibrosis. Studies exploring cell-free mitochondrial DNA as a biomarker in SLE and LN have shown promising but preliminary results, necessitating further validation and standardization. Therapeutically targeting mitochondrial dysfunction in SLE, using drugs like metformin or mTOR inhibitors, shows potential in modulating immune responses and improving clinical outcomes. The interplay between mitochondria, immune dysregulation, and renal involvement in SLE and LN underscores the need for comprehensive research and innovative therapeutic strategies. Understanding mitochondrial dynamics and their impact on immune responses offers promising avenues for developing personalized treatments and non-invasive biomarkers, ultimately improving outcomes for LN patients.

Systemic lupus erythematosus and autoimmune hepatitis overlap disease in a hospitalized systemic lupus erythematosus cohort

Liver dysfunction in systemic lupus erythematosus (SLE) is caused by disease activity or secondary conditions like coexistent autoimmune liver diseases. In Taiwan, despite sporadically reported cases of SLE-autoimmune hepatitis (AIH) overlap disease, larger-scale monocentric investigations for such overlapping patients are not available. Retrospective analyses were performed in a hospitalized SLE cohort with 805 patients for identifying co-existent AIH from 2014 to 2023, focusing on distinct therapeutic modalities and differential diagnosis between SLE-AIH overlap and lupus hepatitis (LH). There were 5 cases (a 0.6% occurrence), all females aged 25–58 years (44 ± 13). Ages for the SLE diagnosis were 19–51 years (30 ± 13), while ages for the AIH diagnosis were 22–57 years (36 ± 14). Contradictory to interface hepatitis in SLE-AIH overlap, liver biopsy only demonstrated non-specific abnormalities in LH. Liver cirrhosis was identified in SLE-AIH overlap but not in LH. After corticosteroids/azathioprine therapy, there were normalized liver function in all LH. In 2 SLE-AIH overlap cases refractory to such therapy, one received B-cell depletion therapy (annual rituximab infusion, 375 mg/m2 weekly × 4) and another accepted living-donor liver transplantation from sibling due to advanced liver cirrhosis, leading to improved hepatic dysfunction in both.

Gender-driven thyroid dysfunction in systemic lupus erythematosus patients: Clinical significance of an overlooked association and global stance

Aim of the workThis study aimed to determine the association of thyroid dysfunction in systemic lupus erythematosus (SLE) patients. Patients and methodsOut of a cohort including 312 adult SLE patients those with thyroid dysfunction (n = 53) were further evaluated. The medical history, clinical examination, laboratory investigations and medications received were recorded. The SLICC damage index (SLICC-DI) was assessed. ResultsThyroid dysfunction formed 17 % of the patients and their mean age was 39.5 ± 11.5 years and disease duration 5.6 ± 3.3 years were comparable to those without thyroid disorder, however female gender was predominantly higher (F:M 52:1 vs 6.2:1, p < 0.0001). The frequency of thyroid dysfunction was alike in Saudi (16 %) and non-Saudi (17.9 %) patients (p = 0.66). The majority of cases (96.2 %) had hypothyroidism, one with autoimmune thyroiditis, while only 2 (3.8 %) had hyperthyroidism. There was a significantly increased frequency of associated neuropsychiatric manifestations (64.2 % vs 45.2 %;p = 0.012), and hematological involvement (32.1 % vs 14.3 %; p = 0.011) and less complement (C4) consumption (15.1 % vs 23.6 %; p = 0.048) in those with thyroid dysfunction compared to those without. The frequency of anti-double stranded deoxyribonucleic acid (anti-dsDNA) positivity tended to be higher (71.7 % vs 66.8 %) and its titre significantly lower (316.3 ± 319.8 IU/ml vs 461.3 ± 459.1; p = 0.013). The SLICC-DI and mortality rate were comparable between groups. Only the presence of proteinuria inversely significantly correlated with the level of T4 (r = -0.31, p = 0.007). ConclusionThyroid dysfunction forms a notable percentage of SLE patients with a prominent female gender propensity. The significant relation of thyroid disorders to neuropsychiatric manifestations, hematological involvement, C4 consumption and anti-dsDNA deserves recognition.

T Cell Dysfunction in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease that can affect many organs in the body with very diverse clinical appearances. The prevalence of SLE in each country varies. The Lupus Foundation of America estimates that around 1.5 million cases occur in America and at least 5 million cases occur worldwide. The pathophysiology of SLE is very complex. The involvement of innate and adaptive immunity in the initiation and pathophysiology of SLE disease shows that there are interactions between leukocytes, cytokines, chemokines and tissue cells. T cells are the main component of the adaptive immune system which can kill infected host cells, activate other immune cells, produce cytokines and regulate immune responses. T cell dysfunction in SLE includes triggering inflammation through the secretion of pro-inflammatory cytokines, helping B cells produce autoantibodies and the accumulation of autoreactive T cells. Aberrations in T cells could be a therapeutic target for development and a potential SLE therapy.

Cognitive dysfunction in systemic lupus erythematosus is associated with disease activity and oxidative stress: a comparative study with rheumatoid arthritis for identifying biomarkers

BackgroundThe prevalence and pathophysiological mechanisms of cognitive deficits (CD) Systemic Lupus Erythematosus (SLE) and Rheumatoid arthritis (RA) are very heterogeneous and poorly understood. We characterized CD in patients with SLE compared with RA patients and healthy controls. We compared the neuropsychological profile of SLE and RA with patients’ oxidative/inflammatory biomarkers for CD.MethodsWe performed a cross-sectional study, including 50 SLE patients, 29 RA patients, and 32 healthy controls. SLEDAI and DAS28 assessed disease activity. SF-36 questionnaire and a battery of cognitive tests were applied to all participants. Blood samples were collected to determine IL-6, S100ß, myeloperoxidase (MPO), malondialdehyde and reduced glutathione (GSH) alterations.ResultsIn the SLE group, higher GSH was associated with the absence of CD (With CD = 69 ± 49, Without CD = 112 ± 81, p = 0.030), while higher IL-6 was associated with the presence of CD in the RA group (With CD = 603 ± 173, Without CD = 431 ± 162, p = 0.032). Regarding specific cognitive domains, in SLE higher MPO was associated with poor performance in reasoning and abstraction (p = 0.039), higher IL-6 was associated with poor performance in inhibitory control and attention (p = 0.031), and higher GSH was associated with better performance in memory(p = 0.021). Higher SLEDAI was associated with poor performance in semantic fluency(p = 0.031), inhibitory control, and attention in the SLE group(p = 0.037). In the RA group, higher DAS-28 was associated with poor performance in executive functions(p = 0.016) and phonemic fluency (p = 0.003).ConclusionSLE patients’ disease activity, inflammatory state, and oxidative stress were associated with CD. In RA patients, CD was associated with disease activity and inflammatory state. These results encourage further studies with larger samples aiming to confirm oxidative stress parameters as biomarkers of CD in SLE patients.

Hypertrophic Pachymeningitis as an Unusual Cause of Headache and Sphincter Dysfunction in Systemic Lupus Erythematosus.

Hypertrophic pachymeningitis is a rare condition of diverse aetiologies.A workup including search for infectious, autoimmune and neoplastic aetiologies should be performed.It is an extremely rare complication in systemic lupus erythematosus and might be the initial and sole clinical manifestation.

Quantitative Assessment of Right Ventricular Function in Patients With Systemic Lupus Erythematosus Using the Novel Non-invasive Pressure-Strain Loop.

Current echocardiography evaluation of right ventricular (RV) function, which heralds the prognosis in patients with systemic lupus erythematosus (SLE), is of limited utility. The non-invasive pressure-strain loop (PSL), an emerging technique, has been found to feasible, sensitive and accurate in the diagnosis of cardiovascular diseases. The aim of this study was to quantitatively evaluate, using the non-invasive PSL, the right ventricular myocardial work (RVMW) in SLE patients. Seventy-five SLE patients were recruited and grouped by pulmonary artery systolic pressure (PASP) into normal (group A, N=26), mild (group B, N=22) and moderate to severe (group C, N=27) groups. Twenty-five healthy volunteers undergoing physical examination were recruited as the control group. Right ventricular global myocardial work index (RVGWI), global constructive work (RVGCW), global wasted work (RVGWW), global work efficiency (RVGWE), global longitudinal strain (RVGLS) and other conventional parameters were measured. There were no differences between group A and the control group with respect to RVLS, RVGLS and all RVMW parameters (all p values > 0.05). RVGWI and RVGCW significantly differed among the other groups (all p values < 0.05). RVGWE was significantly lower and RVGWW was significantly higher in group C than in the control group and groups A and B (all p values < 0.05). Compared with the control group, RVGWW was significantly increased and RVGLS was significantly decreased in group B (all p values < 0.05). All but one RVMW parameter moderately to strongly correlated with SLE disease activity index (SLEDAI) and World Health Organization Functional Class (WHO-FC). RVGWW (area under the receiver operating characteristic curve [AUC]=0.893) and RVGWE (AUC=0.877) were sensitive parameters in detecting earlier cardiac dysfunction in SLE patients. RVGWW and RVGWE serve as sensitive and promising parameters in the integrative analysis of early right ventricular dysfunction in SLE patients. To conclude, non-invasive PSL, the novel method, facilitates the quantitative assessment of RVMW in SLE patients.

Patterns and prevalence of cognitive dysfunction in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, in which cognitive dysfunction is common, but poorly understood. This study aims to characterize the prevalence and patterns of cognitive dysfunction in SLE. SLE patients (n = 95) and demographically matched healthy controls (n = 48) underwent cross-sectional cognitive testing using the 1-hr conventional neuropsychological test battery recommended by the American College of Rheumatology for use in SLE. We used standard deviations (SD) from the healthy control group to define impairment. For each cognitive test we compared SLE and control groups using independent samples t-tests (or alternatives when needed). We performed cluster analysis using a machine learning algorithm to look for patterns of cognitive dysfunction. The SLE group performed significantly worse than healthy controls on every cognitive test. The largest differences were in the domains of verbal fluency, working memory and attention, while fine motor and psychomotor speed were the least affected domains. As expected, the prevalence of cognitive dysfunction varied depending on the SD cut-off used, with 49% of participants being >1.5 SD below the healthy control mean in at least two cognitive domains. Heat mapping showed variability in the pattern of dysfunction between individual patients and cluster analysis confirmed the presence of two clusters of patients, which were those significantly impaired versus those having preserved cognition. Cognitive dysfunction is common in SLE but markedly heterogeneous across both cognitive domains and across the SLE group. Cluster analysis supports the use of a binary definition of cognitive dysfunction in SLE.

Role of Altered Metabolism of Triglyceride-Rich Lipoprotein Particles in the Development of Vascular Dysfunction in Systemic Lupus Erythematosus

Impaired lipid metabolism contributes to accelerated inflammatory responses in addition to promoting the formation of atherosclerosis in systemic lupus erythematosus (SLE). We aimed to evaluate the lipid profile, inflammatory markers, and vascular diagnostic tests in active SLE patients to clarify the association between dyslipidemia and early vascular damage. 51 clinically active SLE patients and 41 age- and gender-matched control subjects were enrolled in the study. Lipoprotein subfractions were detected by Lipoprint. Brachial artery flow-mediated dilation and common carotid intima-media thickness were detected by ultrasonography. Arterial stiffness indicated by augmentation index (Aix) and pulse wave velocity was measured by arteriography. We found significantly higher Aix, higher VLDL ratio, plasma triglyceride, ApoB100, and small HDL, as well as lower HDL-C, large HDL, and ApoA1 in patients with SLE. There was a significant positive correlation of Aix with triglyceride, VLDL, IDL-C, IDL-B, and LDL1. A backward stepwise multiple regression analysis showed IDL-C subfraction to be the best predictor of Aix. Our results indicate that in young patients with SLE, triglyceride-rich lipoproteins influence vascular function detected by Aix. These parameters may be assessed and integrated into the management plan for screening cardiovascular risk in patients with SLE.

Clinical associations of cognitive dysfunction in systemic lupus erythematosus

ObjectiveCognitive dysfunction in SLE is common, but clinical risk factors are poorly understood. This study aims to explore the associations of cognitive dysfunction in SLE with disease activity, organ damage,...

PS-B06-6: LOSS OF SKELETAL MUSCLE MASS INFLUENCES IMMUNE HOMEOSTASIS AND ACCELERATES THE RENAL-RELATED RISK OF HYPERTENSION

Objective: Patients with systemic lupus erythematosus (SLE) are predisposed to developing sarcopenia associated with their underlying proinflammatory condition and a decrease in motility. Also, SLE related autoimmune renal diseases are in part imputed to classical vascular risk factors such as hypertension. The relationship between circulating autoantibodies and hypertension has been recognized. How sarcopenia hastens immune dysfunction in SLE and autoimmunity per se is an underlying cause of hypertension remains uncertain. The present study elucidated the relationship between skeletal muscle loss and systemic immune status with regards to how sarcopenia-mediated immune dysfunction contributes as a critical risk factor in hypertension. Design and Methods: A denervation-induced skeletal muscle loss model was established, and the function of the immune system was evaluated. Systemic immune cell proportions and serum cytokine levels were profiled. Calcium influx and mitochondrial function were also assessed in the T cells. Finally, MRL/lpr mice were used to assess the influence of denervation-induced sarcopenia on SLE-related lupus nephritis progression and circulating autoantibodies, along with the cytokines that contributes to the development of hypertension, such as TNF-α and MCP-1, were evaluated. Results: The results of immune status profiling and functional assessment demonstrated that the loss of skeletal muscle shifts the immune balance in favor of the Th1/Th17 axis. Along with the peak Ca2+ influx, denervation-induced amyotrophy also impaired the spare respiratory capacity in mitochondrial of T cells, as well as the basal respiration and adenosine triphosphate production. The results of proteinuria tracing, serum blood urea nitrogen level, and C3 and IgE deposition in mesangium and capsular adhesion suggests that the sarcopenia promoted nephritis progression. A significant increase of the level in TNF-α, which promotes renal vasoconstriction, a pro-hypertensive effect, was also observed in sarcopenic mice. Conclusion: Consequently, sarcopenia might promote the progression of lupus nephritis because of the enhancement of systemic Th1/Th17 functions and accelerate the deposition of the vascular damage factors. The data herein suggested that the protection from developing hypertension in SLE patient may afforded by preventing skeletal muscle losing. A multidisciplinary approach is required to minimize the overall adverse impact of sarcopenia in the management of SLE-related hypertension.

A cross-sectional study to know the prevalence of thyroid dysfunction in systemic lupus erythematosus

Background: Systemic lupus erythematosus (SLE) is a persistent autoimmune disease, the pathogenesis of which remains elusive. Autoimmune factors may be a cause of SLE and thyroid dysfunction. Many studies have revealed that the prevalence of thyroid disorder is higher in SLE patients than in the general population. SLE is a multisystem and hypothyroidism is an organ specific autoimmune disorder and can occur successively or simultaneously. Aims and Objectives: The aim of the study was to study the prevalence of thyroid disorder in patients with SLE. Materials and Methods: Patients admitted with definite clinical features of SLE and Antinuclear Antibodies positive, in medicine ward and healthy blood donors are taken as control. Sample was tested by fully automated analyzer. Results: Subclinical hypothyroidism was found in 24% of study group and 8% of control group which is statistically significant. Central and secondary hyperthyroidism was found in 10% of study group and 12% of control group but it was statistically insignificant. Several studies have documented an association between SLE and other autoimmune diseases such as Sjogren’s syndrome, autoimmune hemolytic anemia, and antiphospholipid syndrome. Subclinical hypothyroidism was higher than another thyroid dysfunction such as primary, central, and subclinical hypothyroidism was found to be higher in frequency, probably depicting the slow destructive process which is pathognomic of autoimmune thyroiditis. Conclusion: Subclinical hypothyroidism was more prevalent in SLE than that of overt hypothyroidism as compared with general population.

Acute Cerebellitis in A Case of Systemic Sclerosis overlap with Systemic Lupus Erythematosus: Image study

Systemic lupus erythematosus, and systemic sclerosis are chronic autoimmune diseases with symptoms with different degrees of severity and mechanisms. Hence, we present a 36-year-old female with a history of systemic lupus erythematosus which was later overlapped with systemic sclerosis. She complained of vertigo over three months before developing poor gait. She was diagnosed with truncal ataxia due to her ataxic gait and abnormal point motions. Based on the magnetic resonance imaging, a final diagnosis of a cute cerebellar dysfunction in systemic lupus erythematosus was made. Cyclophosphamide was initiated with a single dose of 500 mg which continued for at least three more monthly cycles, and the methylprednisolone pulse was adjusted to 500 mg/day for three days. Due to measures taken to avert a renal crisis caused by scleroderma, the methyl prednisolone dose was deemed to be lower than the adjusted amount (1 g). A follow-up magnetic resonance imaging showed regression of the lesions after treatment, the cerebral lesion had shrunken, and corticomedullary lesion had resolved entirely. Cerebral ataxia could be developed in patients with sytemic lupus erythematosus in terms of vasculitis, diffusely infiltrating glioma, acute disseminated encephalomyelitis, and systemic lupus erythematosus itself. One of the uncommon signs of neuropsychiatric systemic lupus erythematosus is ataxia and cerebellar involvement. The prognosis is generally favorable while receiving immunosuppressive therapy.

Peroxisome proliferator activated receptor-γ agonist pioglitazone improves vascular and metabolic dysfunction in systemic lupus erythematosus

ObjectivesPremature cardiovascular events in systemic lupus erythematosus (SLE) contribute to morbidity and mortality, with no effective preventive strategies described to date. Immune dysregulation and metabolic disturbances appear to play prominent...

Absence of association between nailfold capillary findings and mild cognitive dysfunction in systemic lupus erythematosus.

The role of vascular damage in cognitive dysfunction (CD) in SLE is not entirely understood. Nailfold capillaroscopy (NFC) is a noninvasive method that may aid the description of further vascular contributions to CD in SLE. Therefore, the aim of our study was to examine and compare finger nailfold capillary morphology in subjects with SLE with and without CD. We conducted a cross-sectional study in patients with SLE. Demographic, clinical, and laboratory characteristics were collected. We evaluated nailfold capillary findings including avascular zones, hemorrhage, dilated and tortuous capillaries, disarrangement, crossing, subpapillary venular plexus, branched loops, and shortened loops by NFC. The Montreal Cognitive Assessment (MoCA) scale was used to screen cognitive function. CD was defined as a score < 26/30. Sixty-five females (97.0%) and 2 males (3%) with SLE were analyzed. Means of age and disease duration were 44.3 ± 12.0years and 15.5 ± 7.6years, respectively. Thirty-five (54.7%) patients had CD. The rate of patients with ≥ 1 NFC abnormality was 50% in both patients with and without CD (P = 0.14). Eight (22.8%) patients with CD compared to 1 without (3.5%) displayed dilated capillaries (P = 0.036). Other NFC abnormalities differed between patients with and without CD, but the possible relationships between dilated capillaries and CD disappeared after adjusting by age, diabetes, and hypertension. NFC findings were not associated with mild CD in patients with SLE. Our exploratory data do not support systemic microvasculopathy measured by NFC related to CD in patients with SLE.

Diagnosis and Management of Cognitive Dysfunction In Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease with diverse clinical manifestations. One of the frequent manifestations of SLE is cognitive dysfunction. Cognitive dysfunction is a hidden and often undiagnosed manifestation of SLE but can severely impair quality of life even in mild cognitive dysfunction. Early detection of cognitive dysfunction in SLE patients can determine interventions to help patients adapt to the effects of this decline in cognitive function. However, currently, screening and diagnosis of cognitive dysfunction in SLE are often delayed, and monitoring cannot be done properly. This may be due to the most appropriate assessment tool for cognitive screening in SLE patients has not been agreed upon. The management of cognitive dysfunction in SLE patients today is still challenging due to the SLE pathophysiology is still in debate and research. This literature review will discuss the approach of diagnosis and management of cognitive dysfunction in SLE.

Endothelial Dysfunction in Systemic Lupus Erythematosus and Systemic Sclerosis: A Common Trigger for Different Microvascular Diseases

This review describes the complex interplay between inflammation, vasculopathy and fibrosis that involve the heart and peripheral small vessels, leading to endothelial stiffness, vascular damage, and early aging in patients with systemic lupus erythematosus and systemic sclerosis, which represents two different models of vascular dysfunction among systemic autoimmune diseases. In fact, despite the fact that diagnostic methods and therapies have been significantly improved in the last years, affected patients show an excess of cardiovascular mortality if compared with the general population. In addition, we provide a complete overview on the new techniques which are used for the evaluation of endothelial dysfunction in a preclinical phase, which could represent a new approach in the assessment of cardiovascular risk in these patients.

Cognitive dysfunction in systemic lupus erythematosus: how do we advance our understanding?

Despite the high reported prevalence and burden of cognitive dysfunction in systemic lupus erythematosus (SLE), there is poor understanding of its aetiology, clinical assessment, and management. In part, this lack of understanding is due to conceptual disorganisation in the available literature. In this Review, we address key knowledge gaps in the nomenclature, assessment, and interpretation of cognitive dysfunction in SLE. We apply basic principles of neuropsychology and incorporate lessons from other disease states to recommend principles that can help researchers to design studies in SLE. Better understanding of the trajectory of cognitive dysfunction in SLE will help to inform therapeutic trials, including the appropriate selection of outcome measures to capture clinically meaningful responses.

A Novel Long Noncoding RNA lincRNA00892 Activates CD4+ T Cells in Systemic Lupus Erythematosus by Regulating CD40L.

Objective: The mechanism of CD4+ T-cell dysfunction in systemic lupus erythematosus (SLE) has not been fully understood. Increasing evidence show that long noncoding RNAs (lncRNAs) can regulate immune responses and take part in some autoimmune diseases, while little is known about the lncRNA expression and function in CD4+ T of SLE. Here, we aimed to detect the expression profile of lncRNAs in lupus CD4+ T cells and explore the mechanism that how lincRNA00892 in CD4+ T cells is involved in the pathogenesis of SLE. Methods: The expression profiles of lncRNAs and mRNAs in CD4+ T cells from SLE patients and healthy controls were detected by microarray. LincRNA00892 and CD40L were chosen for validation by quantitative real-time PCR (qRT-PCR). Coexpression network was conducted to predict the potential target genes of lincRNA00892. Then lincRNA00892 was overexpressed in normal CD4+ T cells via lentivirus transfection. The expression of lincRNA00892 was detected by qRT-PCR. The expression of CD40L was detected by qRT-PCR, western blotting, and flow cytometry, respectively. The expression of CD69 and CD23 was measured by flow cytometry. The secretion of IgG was determined by enzyme-linked immunosorbent assay (ELISA). The proteins targeted by lincRNA00892 were measured by RNA pulldown and subsequent mass spectrometry (MS). The interaction between heterogeneous nuclear ribonucleoprotein K (hnRNP K) and lincRNA00892 or CD40L was detected by RNA immunoprecipitation (RIP) assay. Results: A total of 1887 lncRNAs and 3375 mRNAs were found to be aberrantly expressed in CD4+ T cells of SLE patients compared to healthy controls. LincRNA00892 and CD40L were confirmed to be upregulated in CD4+ T cells of SLE patients by qRT-PCR. The lncRNA–mRNA coexpression network analysis indicated that CD40L was a potential target of lincRNA00892. Overexpression of lincRNA00892 enhanced CD40L protein levels while exerting little influence on CD40L mRNA levels in CD4+ T cells. In addition, lincRNA00892 could induce the activation of CD4+ T cells. Furthermore, lincRNA00892 led to the activation of B cells and subsequent secretion of IgG in a CD4+ T-cell–dependent manner. Finally, hnRNP K was found to be among the proteins pulled down by lincRNA00892, and hnRNP K could bind to lincRNA00892 or CD40L directly. Conclusion: Our results showed that the lncRNA expression profile was altered in CD4+ T cells of SLE. LincRNA00892 possibly contributed to the pathogenesis of SLE by targeting hnRNP K and subsequently upregulating CD40L expression to activate CD4+ T and B cells. These provided us a potential target for further mechanistic studies of SLE pathogenesis.