{"title":"Undifferentiated connective tissue disease with an incidental photo-provocation: a case report","authors":"David Roofeh, J. Michelle Kahlenberg","doi":"10.3389/flupu.2023.1223001","DOIUrl":"https://doi.org/10.3389/flupu.2023.1223001","url":null,"abstract":"A female patient with undifferentiated connective tissue disease and no documented history of photosensitivity fastidiously adhered to the rheumatologist's recommendation to avoid UV light exposure. Due to unexpected UV exposure, she developed multiple erythematous/violaceous macules, concerning a cutaneous lupus erythematosus reaction with a chilblain-like appearance. This study highlighted the importance of screening for unintentional photo-provocation in those who are suspected of having or being at risk for developing systemic lupus erythematosus.","PeriodicalId":94014,"journal":{"name":"Frontiers in lupus","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhimin Song, Dae-Goon Yoo, Rachel A. Idol, E. Barbu, C. Jacob, M. Dinauer
{"title":"Lupus-associated NCF2 variant p.R395W in the NADPH oxidase 2 complex results in a reduced production of reactive oxygen species by myeloid cells","authors":"Zhimin Song, Dae-Goon Yoo, Rachel A. Idol, E. Barbu, C. Jacob, M. Dinauer","doi":"10.3389/flupu.2023.1186641","DOIUrl":"https://doi.org/10.3389/flupu.2023.1186641","url":null,"abstract":"The leukocyte NADPH oxidase 2 (NOX2) generates superoxide, and derivative reactive oxygen species play important roles in both host defense and immunoregulation. The rs13306575 genetic variant, resulting in an Arginine395→Tryptophan (R395W) substitution in the NOX2 NCF2 subunit, is associated with an increased risk of lupus in patients of Hispanic-American or of Korean ancestry. Arginine395 resides within the NCF2 PB1 domain and participates in a constitutive high-affinity interaction with the NOX2 NCF4 subunit to stabilize their expression. However, whether this variant impacts NCF2 function and NOX2 activity is unknown. To answer this question, mice expressing NCF2-R395W were generated using CRISPR/Cas9. NCF2 and NCF4 expression were reduced by twofold in neutrophils, macrophages, and dendritic cells homozygous for NCF2-R395W. Moreover, following stimulation with soluble or particulate stimuli, reactive oxygen species production at the plasma membrane and within cells was reduced in all three myeloid lineages expressing NCF2-R395W. Additional studies on Ncf2+/− mice, which have a reduced expression of wild-type NCF2 but not of NCF4, suggest that the reduced expression of both NCF2 and NCF4 contributes to the diminished NOX2 activity in NCF2-R395 mice. These results establish that the lupus-associated rs13306575 p.R395W allele is a functional hypomorph. The findings add to growing evidence implicating deficient NOX2 activity in the pathogenesis of lupus.","PeriodicalId":94014,"journal":{"name":"Frontiers in lupus","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86505500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Scofield, Rohan Sharma, T. Aberle, C. Cooney, J. Kelly, J. Harley, A. Rasmussen
{"title":"Impact of race and ethnicity on family participation in systemic lupus erythematosus genetic studies","authors":"R. Scofield, Rohan Sharma, T. Aberle, C. Cooney, J. Kelly, J. Harley, A. Rasmussen","doi":"10.3389/flupu.2023.1100534","DOIUrl":"https://doi.org/10.3389/flupu.2023.1100534","url":null,"abstract":"Objective Systemic lupus erythematosus (SLE) has a higher prevalence and is more severe in African Americans and Hispanics than in non-Hispanic Whites. To understand the shared and unique genetic risk factors of these populations, an adequate representation of African Americans and Hispanics in clinical and genetic research is indispensable while challenging. The goal of this study was to identify differences in research participation of families of different racial and ethnic backgrounds and the potential causes for the disparities. Methods Families were screened for eligibility to the Lupus Family Registry and Repository (LFRR) after self-referral or physician referral. We recorded the sociodemographic characteristics, self-identified race and ethnicity, ACR-SLE criteria, and the reasons given for not completing study participation for all families. Results A total of 1,472 families (950 non-Hispanic White, 405 African American, and 117 Hispanic) were screened but only 366 completed study participation (25%). Participation rates and reasons for non-participation varied between racial and ethnic groups. The main reason for African American families to not participate was that subjects critical to the family structure declined participation (OR = 1.6, p = 0.0001), while for White families, the main cause was that purported SLE patients did not meet ACR SLE criteria (OR = 1.81, p < 0.00002). Hispanics were the most likely to complete participation (OR = 4.25, p < 0.0001). Conclusions Successful recruitment of patients, families, and specific demographic groups is critical for the study of genetically complex diseases, such as SLE. There are significant disparities in SLE family recruitment across groups of people, likely due to their richly different cultures and environments.","PeriodicalId":94014,"journal":{"name":"Frontiers in lupus","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81235531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frontiers in lupusPub Date : 2023-01-01Epub Date: 2023-11-22DOI: 10.3389/flupu.2023.1244670
Manish Kumar Singh, Guru Prashad Maiti, HariKrishna Reddy-Rallabandi, Mehdi Fazel-Najafabadi, Loren L Looger, Swapan K Nath
{"title":"A Non-Coding Variant in <i>SLC15A4</i> Modulates Enhancer Activity and Lysosomal Deacidification Linked to Lupus Susceptibility.","authors":"Manish Kumar Singh, Guru Prashad Maiti, HariKrishna Reddy-Rallabandi, Mehdi Fazel-Najafabadi, Loren L Looger, Swapan K Nath","doi":"10.3389/flupu.2023.1244670","DOIUrl":"10.3389/flupu.2023.1244670","url":null,"abstract":"<p><p>Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a strong genetic basis. Despite the identification of several single nucleotide polymorphisms (SNPs) near the <i>SLC15A4</i> gene that are significantly associated with SLE across multiple populations, specific causal SNP(s) and molecular mechanisms responsible for disease susceptibility are unknown. To address this gap, we employed bioinformatics, expression quantitative trait loci (eQTLs), and 3D chromatin interaction analysis to nominate a likely functional variant, rs35907548, in an active intronic enhancer of <i>SLC15A4</i>. Through luciferase reporter assays followed by chromatin immunoprecipitation (ChIP)-qPCR, we observed significant allele-specific enhancer effects of rs35907548 in diverse cell lines. The rs35907548 risk allele T is associated with increased regulatory activity and target gene expression, as shown by eQTLs and chromosome conformation capture (3C)-qPCR. The latter revealed long-range chromatin interactions between the rs35907548 enhancer and the promoters of <i>SLC15A4, GLTLD1</i>, and an uncharacterized lncRNA. The enhancer-promoter interactions and expression effects were validated by CRISPR/Cas9 knock-out (KO) of the locus in HL60 promyeloblast cells. KO cells also displayed dramatically dysregulated endolysosomal pH regulation. Together, our data show that the rs35907548 risk allele affects multiple aspects of cellular physiology and may directly contribute to SLE.</p>","PeriodicalId":94014,"journal":{"name":"Frontiers in lupus","volume":"1 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10843804/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139693721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Frontiers in lupusPub Date : 2023-01-01Epub Date: 2023-10-03DOI: 10.3389/flupu.2023.1234578
Iouri Chepelev, Isaac T W Harley, John B Harley
{"title":"Modeling of horizontal pleiotropy identifies possible causal gene expression in systemic lupus erythematosus.","authors":"Iouri Chepelev, Isaac T W Harley, John B Harley","doi":"10.3389/flupu.2023.1234578","DOIUrl":"10.3389/flupu.2023.1234578","url":null,"abstract":"<p><strong>Background: </strong>Systemic lupus erythematosus (SLE) is a chronic autoimmune condition with complex causes involving genetic and environmental factors. While genome-wide association studies (GWASs) have identified genetic loci associated with SLE, the functional genomic elements responsible for disease development remain largely unknown. Mendelian Randomization (MR) is an instrumental variable approach to causal inference based on data from observational studies, where genetic variants are employed as instrumental variables (IVs).</p><p><strong>Methods: </strong>This study utilized a two-step strategy to identify causal genes for SLE. In the first step, the classical MR method was employed, assuming the absence of horizontal pleiotropy, to estimate the causal effect of gene expression on SLE. In the second step, advanced probabilistic MR methods (PMR-Egger, MRAID, and MR-MtRobin) were applied to the genes identified in the first step, considering horizontal pleiotropy, to filter out false positives. PMR-Egger and MRAID analyses utilized whole blood expression quantitative trait loci (eQTL) and SLE GWAS summary data, while MR-MtRobin analysis used an independent eQTL dataset from multiple immune cell types along with the same SLE GWAS data.</p><p><strong>Results: </strong>The initial MR analysis identified 142 genes, including 43 outside of chromosome 6. Subsequently, applying the advanced MR methods reduced the number of genes with significant causal effects on SLE to 66. PMR-Egger, MRAID, and MR-MtRobin, respectively, identified 13, 7, and 16 non-chromosome 6 genes with significant causal effects. All methods identified expression of <i>PHRF1</i> gene as causal for SLE. A comprehensive literature review was conducted to enhance understanding of the functional roles and mechanisms of the identified genes in SLE development.</p><p><strong>Conclusions: </strong>The findings from the three MR methods exhibited overlapping genes with causal effects on SLE, demonstrating consistent results. However, each method also uncovered unique genes due to different modelling assumptions and technical factors, highlighting the complementary nature of the approaches. Importantly, MRAID demonstrated a reduced percentage of causal genes from the Major Histocompatibility complex (MHC) region on chromosome 6, indicating its potential in minimizing false positive findings. This study contributes to unraveling the mechanisms underlying SLE by employing advanced probabilistic MR methods to identify causal genes, thereby enhancing our understanding of SLE pathogenesis.</p>","PeriodicalId":94014,"journal":{"name":"Frontiers in lupus","volume":"1 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10554754/pdf/nihms-1930920.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41109237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}