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Mariana J Kaplan

Publications and source records attributed to Mariana J Kaplan.

18 recordsLinked to original sources
PubMed2026

Dysregulation of U12-Type Splicing in Lupus Neutrophils.

OBJECTIVE: Neutrophil dysfunction is a hallmark of systemic lupus erythematosus (SLE), but its molecular basis remains unclear. This study explores transcriptional and posttranscriptional changes in low-density granulocytes (LDGs), a proinflammatory neutrophil subset expanded in SLE, focusing on NADPH oxidase (Nox) function and minor intron splicing. METHODS: LDGs and normal-density granulocytes (NDGs) were isolated from patients with SLE and healthy controls (HCs). CYBA (p22phox) expression was evaluated at transcript and protein levels. Nox activity was measured using luminol assays. Bulk RNA sequencing (RNA-seq) and rMATS software were used to assess alternative splicing, particularly of U12-type intron-containing genes. RESULTS: CYBA expression was reduced in SLE LDGs (n = 11) compared to SLE and HC NDGs (n = 6), with levels resembling those in chronic granulomatous disease neutrophils. SLE LDGs exhibited impaired Nox activity (n = 7 SLE, n = 12 HC). CYBA is a U12 intron-containing gene, and transcriptomic analysis revealed broad down-regulation of this gene class in SLE LDGs, suggesting minor spliceosome dysfunction. rMATS analysis showed increased U12-type intron retention and widespread splicing defects-including exon skipping and mutually exclusive exon use-in genes such as GBP5, MAEA, and STX10. These abnormalities were validated in an independent long-read RNA-seq data set from SLE peripheral blood mononuclear cells. Importantly, splicing disruptions correlated with disease activity and autoantibody profiles. CONCLUSION: Impaired U12-dependent splicing may contribute to neutrophil dysfunction in SLE, potentially via defective oxidative burst and altered immune regulation. These findings highlight the minor spliceosome as a novel player in lupus pathogenesis.

Humans↗
PubMed2025

Next generation sequencing analysis reveals complex genetic architecture of childhood-onset systemic lupus erythematosus.

OBJECTIVES: Our current understanding of the genetic architecture of childhood-onset SLE (cSLE) is limited by a dearth of comprehensive genomic studies in cSLE. We have quantified the number of known rare and common SLE risk variants in a diverse cSLE cohort. We characterised type I interferon (IFN) gene expression scores along with genomic data. METHODS: We performed whole genome sequencing on 83 patients with cSLE and 109 unaffected parents and analysed sequences for known common and rare SLE-associated risk variants. Type I IFN gene expression was quantified on a subset of patients. We investigated the relationship between clinical phenotype, genomic profile and type I IFN signatures in this cohort. RESULTS: Patients with cSLE were enriched for common SLE risk variants compared with unaffected parents and controls. We identified rare SLE risk variants in 11% of individuals with cSLE; those with rare variants had earlier disease onset (<12 years) than those without variants. Patients with cSLE had elevated type I IFN gene expression compared with unaffected parents and controls, even though most patients were treated with immunosuppressive therapy. CONCLUSIONS: Patients with cSLE from this ancestrally and geographically diverse cohort are enriched for common cSLE risk variants compared with controls, and 11% carry a rare variant in known monogenic SLE risk genes. The relationship between rare and common risk variant burden is more complex than previously hypothesised. Our findings indicate that studying patients with cSLE is important for understanding genetic contributions to SLE pathogenesis.

Humans↗
PubMed2021

Somatic Mutations in UBA1 Define a Distinct Subset of Relapsing Polychondritis Patients With VEXAS.

OBJECTIVE: Somatic mutations in UBA1 cause a newly defined syndrome known as VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic syndrome). More than 50% of patients currently identified as having VEXAS met diagnostic criteria for relapsing polychondritis (RP), but clinical features that characterize VEXAS within a cohort of patients with RP have not been defined. We undertook this study to define the prevalence of somatic mutations in UBA1 in patients with RP and to create an algorithm to identify patients with genetically confirmed VEXAS among those with RP. METHODS: Exome and targeted sequencing of UBA1 was performed in a prospective observational cohort of patients with RP. Clinical and immunologic characteristics of patients with RP were compared based on the presence or absence of UBA1 mutations. The random forest method was used to derive a clinical algorithm to identify patients with UBA1 mutations. RESULTS: Seven of 92 patients with RP (7.6%) had UBA1 mutations (referred to here as VEXAS-RP). Patients with VEXAS-RP were all male, were on average &#x2265;45 years of age at disease onset, and commonly had fever, ear chondritis, skin involvement, deep vein thrombosis, and pulmonary infiltrates. No patient with VEXAS-RP had chondritis of the airways or costochondritis. Mortality was greater in VEXAS-RP than in RP (23% versus 4%; P = 0.029). Elevated acute-phase reactants and hematologic abnormalities (e.g., macrocytic anemia, thrombocytopenia, lymphopenia, multiple myeloma, myelodysplastic syndrome) were prevalent in VEXAS-RP. A decision tree algorithm based on male sex, a mean corpuscular volume >100 fl, and a platelet count <200 &#xd7;103 /&#x3bc;l differentiated VEXAS-RP from RP with 100% sensitivity and 96% specificity. CONCLUSION: Mutations in UBA1 were causal for disease in a subset of patients with RP. This subset of patients was defined by disease onset in the fifth decade of life or later, male sex, ear/nose chondritis, and hematologic abnormalities. Early identification is important in VEXAS given the associated high mortality rate.

Aged↗
PubMed2006

Aberrant phenotype and function of myeloid dendritic cells in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is characterized by a systemic autoimmune response with profound and diverse T cell changes. Dendritic cells (DCs) are important orchestrators of immune responses and have an important role in the regulation of T cell function. The objective of this study was to determine whether myeloid DCs from individuals with SLE display abnormalities in phenotype and promote abnormal T cell function. Monocyte-derived DCs and freshly isolated peripheral blood myeloid DCs from lupus patients displayed an abnormal phenotype characterized by accelerated differentiation, maturation, and secretion of proinflammatory cytokines. These abnormalities were characterized by higher expression of the DC differentiation marker CD1a, the maturation markers CD86, CD80, and HLA-DR, and the proinflammatory cytokine IL-8. In addition, SLE patients displayed selective down-regulation of the maturation marker CD83 and had abnormal responses to maturation stimuli. These abnormalities have functional relevance, as SLE DCs were able to significantly increase proliferation and activation of allogeneic T cells when compared with control DCs. We conclude that myeloid DCs from SLE patients display significant changes in phenotype which promote aberrant T cell function and could contribute to the pathogenesis of SLE and organ damage.

Adult↗
PubMed2006

Accelerated macrophage apoptosis induces autoantibody formation and organ damage in systemic lupus erythematosus.

Increased monocyte/macrophage (Mphi) apoptosis occurs in patients with systemic lupus erythematosus (SLE) and is mediated, at least in part, by an autoreactive CD4(+) T cell subset. Furthermore, autoreactive murine CD4(+) T cells that kill syngeneic Mphi in vitro induce a lupus-like disease in vivo. However, it is unclear whether increased Mphi apoptosis in SLE per se is sufficient to accelerate/promote autoimmunity. We have investigated whether increased Mphi apoptosis in vivo, induced by the administration of clodronate liposomes, can exacerbate the autoimmune phenotype in NZB x SWR (SNF(1)) lupus-prone mice, and induce autoantibody production in haplotype-matched BALB/c x DBA1 (DBF(1)) non-lupus-prone mice. Lupus-prone mice SNF(1) mice that were treated with clodronate liposomes, but not mice treated with vehicle, developed significant increases in autoantibodies to dsDNA, nucleosomes, and the idiotypically related family of nephritic Abs Id(LN)F(1), when compared with untreated SNF(1) mice. Furthermore, clodronate treatment hastened the onset of proteinuria and worsened SNF(1) lupus nephritis. When compared with vehicle-treated controls, clodronate-treated non-lupus-prone DBF(1) mice developed significantly higher levels of anti-nucleosome and Id(LN)F(1) Abs but did not develop lupus nephritis. We propose that Mphi apoptosis contributes to the pathogenesis of autoantibody formation and organ damage through both an increase in the apoptotic load and impairment in the clearance of apoptotic material. This study suggests that mechanisms that induce scavenger cell apoptosis, such as death induced by autoreactive cytotoxic T cells observed in SLE, could play a pathogenic role and contribute to the severity of the disease.

Animals↗
PubMed2006

Cardiovascular disease in rheumatoid arthritis.

PURPOSE OF REVIEW: Individuals with rheumatoid arthritis are at increased risk for morbidity and mortality from cardiovascular disease (CVD). The purpose of this review is to discuss recent advances in our understanding of the pathogenesis, prevalence, treatment, and prevention of accelerated atherosclerotic disease in rheumatoid arthritis. RECENT FINDINGS: Recent reports have highlighted the increased risk for silent myocardial infarction and sudden death in rheumatoid arthritis, and the potential roles of traditional and nontraditional risk factors for CVD, including abnormal revascularization of damaged peripheral blood vessels and genetic polymorphisms. Several studies have also added important information on the possible role of anti-tumor necrosis factor-alpha therapy, other disease modifying antirheumatic drugs, and nonsteroidal anti-inflammatory drugs in decreasing CVD risk. SUMMARY: The pathogenic mechanisms involved in accelerated cardiovascular complications in rheumatoid arthritis appear to be complex and multifactorial. Both traditional and nontraditional risk factors potentially contribute to the increased cardiovascular risk. Good control of the inflammation, immunologic disturbances, and metabolic changes seen in rheumatoid arthritis are crucial in the prevention of this potentially lethal complication. There is a need for heightened awareness of the increased risk for silent ischemia, early myocardial infarction, and sudden death. Further exploration of the mechanisms of vascular repair and their potential role in premature atherosclerosis is needed.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2005

Plasminogen activator inhibitor-1 is associated with impaired endothelial function in women with systemic lupus erythematosus.

Endothelial function, measured noninvasively by brachial artery flow-mediated dilatation (FMD), has been shown to be impaired in patients with systemic lupus erythematosus (SLE). We hypothesized that depressed FMD in SLE patients is associated with increased levels of plasminogen activator inhibitor-1 (PAI-1), an inhibitor of fibrinolysis and regulator of vasoactivity. In this cross-sectional study of female SLE patients under the age of 55, putative markers of cardiovascular disease (CVD) such as PAI-1 were measured in addition to lupus-related disease activity (SLEDAI). The primary outcome, FMD, was measured using high-resolution ultrasound of the brachial artery gated to the R wave to determine endothelial-dependent vasomotion. Endothelial-independent vasomotion was measured in response to nitroglycerin (NMD). Seventy-six female SLE patients, mean age 38.3 +/- 9.4 years, were included. All patients demonstrated normal NMD responses, indicating that depression of FMD was related to decreased endothelial nitric oxide production. Increased PAI-1 was related to depressed FMD by univariate regression (P = 0.004). In a multivariable regression model adjusting for t-PA (tissue plasminogen activator)/PAI-1 ratio, SLEDAI, age at visit, family history of cardiovascular disease, SLE disease duration and body mass index, every 1 ng/mL increase in PAI-1 was associated with a reduction of 0.07 units FMD (P = 0.039). PAI-1 was associated with impaired endothelial dysfunction, after controlling for several potential confounders. Given the high incidence of cardiovascular disease in SLE, further investigation of the role of subclinical markers of CVD is needed.

Adult↗
PubMed2005

FK-778 Astellas.

Astellas, under license from sanofi-aventis, is developing the immunosuppressant compound FK-778 as a potential treatment for organ transplantation. By February 2005, phase II trials were ongoing both in the US and in Europe.

Alkynes↗
PubMed2004

Demethylation of promoter regulatory elements contributes to perforin overexpression in CD4+ lupus T cells.

Inhibiting DNA methylation in CD4+ T cells causes aberrant gene expression and autoreactive monocyte/macrophage killing in vitro, and the hypomethylated cells cause a lupus-like disease in animal models. Similar decreases in T cell DNA methylation occur in idiopathic lupus, potentially contributing to disease pathogenesis. The genes affected by DNA hypomethylation are largely unknown. Using DNA methylation inhibitors and oligonucleotide arrays we have identified perforin as a methylation-sensitive gene. Our group has also reported that DNA methylation inhibitors increase CD4+ T cell perforin by demethylating a conserved methylation-sensitive region that is hypomethylated in primary CD8+ cells, which express perforin, but is largely methylated in primary CD4+ cells, which do not. As lupus T cells also have hypomethylated DNA and promiscuously kill autologous monocytes/macrophages, we hypothesized that perforin may be similarly overexpressed in lupus T cells and contribute to the monocyte killing. We report that CD4+ T cells from patients with active, but not inactive, lupus overexpress perforin, and that overexpression is related to demethylation of the same sequences suppressing perforin transcription in primary CD4+ T cells and demethylated by DNA methylation inhibitors. Further, the perforin inhibitor concanamycin A blocks autologous monocyte killing by CD4+ lupus T cells, suggesting that the perforin is functional. We conclude that demethylation of specific regulatory elements contributes to perforin overexpression in CD4+ lupus T cells. Our results also suggest that aberrant perforin expression in CD4+ lupus T cells may contribute to monocyte killing.

Adult↗
PubMed2004

Endothelial cell apoptosis in systemic lupus erythematosus: a common pathway for abnormal vascular function and thrombosis propensity.

Women with systemic lupus erythematosus (SLE) are at risk for premature atherothrombosis independent of Framingham risk factors. We investigated whether endothelial cell (EC) apoptosis predicts abnormal vasomotor tone and contributes to circulating tissue factor (TF) levels in this disease. Brachial artery flow-mediated dilation (FMD) and nitroglycerin-mediated dilation were determined in women with SLE, healthy control subjects, and subjects with coronary artery disease (CAD) (n = 43/group). Quantification of circulating apoptotic ECs was performed by flow cytometry (CD146(+) cells that stained for Annexin V [CD146(AnnV+)]) and immunofluorescent microscopy. Plasma TF was measured by enzyme-linked immunosorbent assay (ELISA). Compared with healthy control and CAD subjects, patients with SLE had higher numbers of circulating CD146(AnnV+) cells (10 +/- 3, 18 +/- 5, and 89 +/- 32 cells/mL, respectively, mean +/- SEM; P <.01). Increased CD146(AnnV+) cells correlated strongly with abnormal vascular function (P =.037). After adjusting for known predictors of endothelial function, CD146(AnnV+) was the only variable that predicted FMD (beta = -4.5, P <.001). Increased CD146(AnnV+) was strongly associated with elevated levels of circulating TF (r =.46, P =.002). Circulating apoptotic ECs are elevated in young women with SLE and strongly correlate with markedly abnormal vascular function and elevated TF levels. Heightened endothelial apoptosis may represent an important mechanism for development of atherothrombosis in SLE.

Adult↗
PubMed2003

Effects of cilostazol in patients with Raynaud's syndrome.

Raynaud's syndrome (RS), which is characterized by recurrent episodes of vasospasm with exposure to cold, may occur alone (primary RS) or in association with connective tissue diseases or other underlying conditions (secondary RS). We investigated the effect of cilostazol on vessel wall responses in RS. Patients were diagnosed (primary or secondary RS associated with connective tissue diseases) and randomized to placebo or cilostazol 100 mg twice daily for 6 weeks in a double-blind manner. Brachial artery vasoreactivity, laser Doppler fluxmetry, and cold pressor testing (CPT) were performed at study initiation and completion. Symptoms were assessed using standardized questionnaires. Forty subjects completed the study (19 with primary RS and 21 with secondary RS). Cilostazol significantly increased the mean brachial artery diameter at 6 weeks (primary RS, p = 0.006; secondary RS, p = 0.06). There was no change in median flow-mediated dilation (FMD) with cilostazol in primary RS (25th, 75th percentiles) (4.06% [2.5, 6.1] to -0.77% [-2.4, 3.4] or secondary RS (2.2% [0.05, 6.3] to 2.95% [1.7, 7.4]). There were no changes in nitroglycerin-mediated dilation or microvascular flow indexes in either cohort. In patients with primary RS, cilostazol treatment yielded a positive change in the slope of brachial responsiveness to CPT (increase of 0.32 mm/min; p = 0.002 vs placebo). Cilostazol treatment remained significantly associated with increased brachial artery diameter when controlling for baseline values (p = 0.018). Cilostazol increased conduit vessel diameter in patients with primary and secondary RS, with a favorable impact on conduit vessel responsiveness to cold in patients with primary RS without affecting microvascular flow or symptoms.

Adult↗
PubMed2003

Increased asymmetric dimethylarginine and endothelin 1 levels in secondary Raynaud's phenomenon: implications for vascular dysfunction and progression of disease.

OBJECTIVE: To compare microvascular and macrovascular functions in a cohort of patients with primary and secondary Raynaud's phenomenon (RP) who were matched for demographic, risk factor, and severity profiles. METHODS: Forty patients with primary or secondary RP matched for vascular risk factors and severity scores underwent testing of endothelial function and cold pressor responsiveness of the brachial artery. Microvascular perfusion of the digital vasculature was assessed using laser Doppler fluxmetry in response to reactive hyperemia. Plasma was assayed for endothelin 1 (ET-1), asymmetric dimethylarginine (ADMA), intercellular adhesion molecule 1, vascular cell adhesion molecule 1 (VCAM-1), and monocyte chemoattractant protein 1 (MCP-1). RESULTS: Patients with RP had abnormal vasoconstrictor responses to cold pressor tests (CPT) that were similar in primary and secondary RP. There were no differences in median flow-mediated and nitroglycerin-mediated dilation or CPT of the brachial artery in the 2 populations. Patients with secondary RP were characterized by abnormalities in microvascular responses to reactive hyperemia, with a reduction in area under the curve adjusted for baseline perfusion, but not in time to peak response or peak perfusion ratio. Plasma ET-1, ADMA, VCAM-1, and MCP-1 levels were significantly elevated in secondary RP compared with primary RP. There was a significant negative correlation between ET-1 and ADMA values and measures of microvascular perfusion but not macrovascular endothelial function. CONCLUSION: Secondary RP is characterized by elevations in plasma ET-1 and ADMA levels that may contribute to alterations in cutaneous microvascular function.

Adult↗
PubMed2002

The apoptotic ligands TRAIL, TWEAK, and Fas ligand mediate monocyte death induced by autologous lupus T cells.

Individuals with systemic lupus erythematosus show evidence of a significant increase in monocyte apoptosis. This process is mediated, at least in part, by an autoreactive T cell subset that kills autologous monocytes in the absence of nominal Ag. We have investigated the apoptotic pathways involved in this T cell-mediated process. Expression of the apoptotic ligands TRAIL, TNF-like weak inducer of apoptosis (TWEAK), and Fas ligand on lupus T cells was determined, and the role of these molecules in the monocyte apoptotic response was examined. We report that these apoptotic ligands mediate the autologous monocyte death induced by lupus T cells and that this cytotoxicity is associated with increased expression of these molecules on activated T cells, rather than with an increased susceptibility of lupus monocytes to apoptosis induced by these ligands. These results define novel mechanisms that contribute to increased monocyte apoptosis characterizing patients with lupus. We propose that this mechanism could provide a source of potentially antigenic material for the autoimmune response and interfere with normal clearing mechanisms.

Adult↗
PubMed2002

The liver is a common non-exocrine target in primary Sjögren's syndrome: a retrospective review.

BACKGROUND: The autoimmune destruction of exocrine glands that defines primary Sjögren's syndrome (1 degrees SS) often extends to non-exocrine organs including the liver. We aimed to determine the prevalence of liver disease in patients with 1 degrees SS and to evaluate the association of this complication with other non-exocrine features and serologic markers of autoimmunity and systemic inflammation. METHODS: We reviewed 115 charts of patients with 1 degrees SS and further analyzed the 73 cases that fulfilled the European Epidemiology Center Criteria, seeking evidence for clinical and subclinical liver disease. RESULTS: Liver function tests had been determined in 59 of the 73 patients. Of those, 29 patients (49.1%) had abnormal liver function tests including 20.3% with clinically overt hepatic disease. Liver disease was the most common non-exocrine feature in this cohort. Risk factors for abnormal liver function tests were distributed similarly between the patients with and without liver disease. In 60% of patients with abnormal liver function tests no explanation for this complication was found except for 1 degrees SS. Liver involvement was significantly more common in 1 degrees SS patients who also had evidence of lung, kidney and hematological abnormalities. Patients with abnormal liver function tests were also more likely to have an elevated sedimentation rate and a positive anti-ENA during the course of their disease. CONCLUSION: Liver involvement is a common complication in 1 degrees SS. Its presence correlates with systemic disease. We consider that this complication should be routinely sought in patients with 1 degrees SS, especially when a positive anti-ENA or evidence of systemic inflammation is found.

Biopsy↗