Faculty Bibliography

Background/Purpose: Interferon (IFN)-alpha contributes to susceptibility and severe manifestations in systemic lupus erythematosus (SLE). The PRKG1 rs7897633 variant has been previously identified as the top hit in European ancestry patients with SLE and high IFN-alpha compared to those with low circulating IFN activity. However, the mechanisms by which PRKG1 polymorphisms impact the immune system remain unknown. PRKG1 codes for the cGMP-dependent protein kinase I (PKGI). Activation of PKGI leads to VASP phosphorylation, and the inhibition of RhoA and Rho-associated kinases (ROCK). A subgroup of patients with SLE exhibit higher ROCK activity in circulating immune cells compared to healthy controls. ROCK inhibition decreases IFN-alpha production and ameliorates disease in murine models of lupus. Accordingly, we aimed to assess whether the PRKG1 gene variant was associated with decreased gene expression and activity of PRKG1, hyperactivation of the ROCK pathway, and altered response to type I IFN.
Method(s): We used B lymphoblastoid cell lines (LCL) derived from healthy subjects of European ancestry (Coriell repositories) homozygous (AA or CC) and heterozygous (AC) at the rs7897633 SNP for all experiments. Gene expression of PRKG1, RHOA, and ROCK was assessed by RT-qPCR using gene-specific primers, normalized by GAPDH, and measured by the 2-DELTADELTACT method. IFN score at baseline and after treatment of LCL with increasing doses of IFN-alpha was measured by quantifying 3 canonical IFN-stimulated genes (IFIT1, MX1 and PKR) and summing to generate a score reflecting the degree of IFN-induced gene expression in the cells. Abundance of PKGI and VASP phosphorylation (as a surrogate of PKGI activity) were determined by Western blotting at baseline and after treatment with a PKGI agonist. ROCK2 enzymatic activity was performed by a colorimetric assay (Cell Biolabs). Unstimulated and stimulated cells were compared among PRKG1 genotype categories. Statistically significant differences were determined by Mann Whitney U test or sum-of-squares F test, as appropriate.
Result(s): PRKG1 expression was lower in the homozygous AA genotype as compared with the homozygous CC genotype in LCL (p< 0.05). In contrast, ROCK expression was higher in LCL with the AA rs7897633 genotype (p< 0.05). Compared to LCL with the homozygous AA variant of rs7897633, homozygous CC LCL have greater abundance of PKGI, phosphorylated VASP/total VASP ratio in response to a PKGI agonist (indicating increased PKGI activity), and lower baseline ROCK activity (sum-of-squares F test, p< 0.05). The IFN score was significantly higher in the homozygous CC allele LCL, both at baseline and with increasing doses of IFN-alpha, suggesting increased sensitivity to type I IFN (p< 0.05).
Conclusion(s): PRKG1 AA genotype associates with lower PRKG1 and higher ROCK mRNA expression, decreased PKGI abundance and activity, and greater ROCK baseline activity. In contrast, the rs7897633 CC genotype is associated with increased response to IFNalpha. Overall, these findings suggest an important role of genetic variation at PRKG1 in modulating the RhoA-ROCK pathway and regulating response to type I IFNs in LCL, which may have therapeutic implications in patients with SLE

Background/Purpose: Type I interferon (IFN) is critical in our defense against viral infections. Increased type I IFN pathway activation is a genetic risk factor for systemic lupus erythematosus (SLE), and a number of common alleles contribute to the genetic high IFN trait. In this study, we examine whether these common gain-of-function alleles in the type I IFN pathway are associated with protection from mortality in acute COVID-19.
Method(s): We studied IFN pathway SLE risk genes in patients with acute COVID-19 admitted to NYU Langone hospitals (751 European-American and 398 African-American ancestry). The samples were genotyped using low depth sequencing and imputation, and we analyzed data from the following SNPs: IRF5 (rs2004640, rs3807306, rs10488631, rs2280714), IRF7/PHRF (rs1131665, rs4963128), IRF8 (rs17445836, rs12444486), and PRKG1 (rs7897633). Ancestral backgrounds were analyzed separately, and mortality after acute COVID-19 was the primary outcome.
Result(s): We observed specific IRF5 haplotypes that are protective against SLE risk were associated with increased risk of mortality in acute COVID-19 patients in European-American ancestry (OR=3.74, p=0.015). Alleles of PRKG1 were also associated with mortality from COVID-19 in the European-American ancestry cohort (OR=1.80, p=0.0057), and this risk factor was particularly strong in younger patients (OR=29.2, p=0.01 in ages 45-54). IRF8 genotype at rs1244486 was associated with protection from mortality in COVID-19 in African-American subjects aged 65 and older (OR=0.34, p=0.04).
Conclusion(s): We find that a number of type I IFN pathway genes associated with risk of SLE also modulate risk of death during acute COVID-19. Similar to their associations with SLE, these alleles are variably associated with COVID-19 mortality across ancestral backgrounds, suggesting ancestral differences in the genetic regulation of the IFN pathway. These data confirm the critical role of the IFN pathway in our defense against viral infections, and support the idea that some common SLE risk alleles exert protective effects in anti-viral immunity

BACKGROUND:Peripheral vascular diseases may induce chronic ischemia and cellular injury distal to the arterial obstruction. Cellular senescence involves proliferation arrest in response to stress, which can damage neighboring cells. Renal artery stenosis (RAS) induces stenotic-kidney dysfunction and injury, but whether these arise from cellular senescence and their temporal pattern remain unknown. METHODS AND RESULTS/RESULTS:)-positive cells and alleviating renal dysfunction and damage. Unbiased single-cell RNA-sequencing in freshly-dissociated cells from healthy and stenotic mouse kidneys identified stenotic-kidney epithelial cells undergoing both mesenchymal transition and senescence. Like mice, injured human stenotic kidneys exhibited cellular senescence, suggesting that this process is conserved. CONCLUSIONS:) expression, is associated with renal dysfunction and injury in chronic ischemia. These findings support development of senolytic strategies to delay chronic ischemic renal injury.

T-cell dysregulation has been implicated in the loss of tolerance and overactivation of B cells in systemic lupus erythematosus (SLE). Recent studies have identified T-cell subsets and genetic, epigenetic, and environmental factors that contribute to pathogenic T-cell differentiation, as well as disease pathogenesis and clinical phenotypes in SLE. Many therapeutics targeting T-cell pathways are under development, and although many have not progressed in clinical trials, the recent approval of the calcineurin inhibitor voclosporin is encouraging. Further study of T-cell subsets and biomarkers of T-cell action may pave the way for specific targeting of pathogenic T-cell populations in SLE.

As the world navigates the Coronavirus disease 2019 (COVID-19) pandemic, there is a growing need to assess its impact in patients with autoimmune rheumatic diseases, such as systemic lupus erythematosus (SLE). Patients with SLE are a unique population when considering the risk of contracting COVID-19 and infection outcomes. The use of systemic glucocorticoids and immunosuppressants, and underlying organ damage from SLE are potential susceptibility factors. Most patients with SLE have evidence of high type I IFN activity, which may theoretically act as an antiviral line of defense or contribute to the development of a deleterious hyperinflammatory response in COVID-19. Other immunopathogenic mechanisms of SLE may overlap with those described in COVID-19, and thus studies in SLE could provide some insight into immune responses occurring in severe cases of the viral infection. We reviewed the literature to date on COVID-19 in patients with SLE and provide an in-depth review of current research in the area, including immune pathway activation, epidemiology, clinical features, outcomes, and the psychosocial impact of the pandemic in those with autoimmune disease.

BACKGROUND:The objective of the study was to explore the disease pathways activated in the inflammatory foci of skin lesions in cutaneous lupus erythematosus (CLE) and dermatomyositis (DM). METHODS:Skin biopsies acquired from active CLE and DM lesions, patient (PC), and also healthy controls (HC) were investigated. Biopsy sections were examined by a pathologist, inflammatory foci were laser micro-dissected and captured, and proteins within captured tissue were detected in an unbiased manner by mass spectrometry. Protein pathway analysis was performed by the string-db.org platform. Findings of interest were confirmed by immunohistochemistry (IHC). RESULTS:Proteome investigation identified abundant expression of interferon-regulated proteins (IRP) as a common feature of CLE and DM. Interleukin (IL)-16 was the only abundant cytokine differentially expressed in CLE compared to DM. Caspase-3, an enzyme that cleaves IL-16 into its active form, was detected in low levels. Significantly higher proportion of IL-16- and caspase-3-positive cells was identified in CLE lesions in comparison with DM, PC, and HC. Proteomic results indicate more abundant complement deposition in CLE skin lesions. CONCLUSIONS:Using unbiased mass spectrometry investigation of CLE and DM inflammatory infiltrates, we confirmed that high IRP expression is a common feature of both CLE and DM, while IL-16 is the only differentially expressed cytokine in CLE. IHC confirmed high expression of IL-16 and caspase-3 in CLE. Our novel molecular findings indicate that IL-16 detection could be useful in differential diagnostics between the two conditions that can display similar histopathological appearance. IL-16 could be of interest as a future therapeutic target for CLE.

Systemic lupus erythematosus (SLE) is a complex and heterogeneous systemic autoimmune disease associated with innate and adaptive immune dysregulation. SLE occurs primarily in females of childbearing age, with increased prevalence and severity in minority populations. Despite improvements in treatment modalities, SLE patients frequently experience periods of heightened disease activity and flare that can lead to permanent organ damage, increased morbidity, and early mortality. Such outcomes impair quality of life and inflict a significant socioeconomic burden. Predicting changes in SLE disease activity could allow for closer monitoring and preemptive treatment, but existing clinical, demographic and serologic markers have been only modestly predictive. Novel, proactive approaches to clinical disease management are thus critically needed. Panels of blood biomarkers can detect a breadth of immune pathway dysregulation that captures SLE heterogeneity and disease activity. Alterations in the balance of pro-inflammatory and regulatory soluble mediators have been associated with changes in clinical disease activity and are detectable several weeks prior to clinical flare occurrence. A soluble mediator score has been highly predictive of impending flare in both European American and African American SLE patients, and this score does not require a priori knowledge of specific pathway activation in the patient. We review current concepts of disease activity and flare in SLE, focusing on the potential of novel blood biomarkers to characterize and predict changes in disease activity. Measuring the disordered immune response in SLE in this way promises to improve disease management and prevent organ damage in SLE.

Cryopyrin-associated periodic syndromes (CAPS) are a group of autoinflammatory diseases associated with NLRP3 gain of function mutations. CAPS associated mutations are found predominantly in exon 3. The objective of this study is to describe a new variant on NRLP3 gene and its phenotype. Case report description of a new NRLP3 pathogenic variant and literature case-based search through INFEVERS database. A 21-year old male who presented multiple tonic-clonic seizures on his 3rd day of life. At age 2, he had recurrent central facial palsy, high fever (40 °C), painful and persistent oral ulcers, abdominal pain, nausea and vomiting, and delayed neuropsychomotor development, with polyarthritis in wrists and knees. Over the years, several symptoms were observed: livedo reticularis, Raynaud's phenomenon, positive pathergy test, heat allodynia, extremely painful genital ulcers, and sporadic conjunctivitis. Laboratory studies revealed persistently elevated inflammatory markers and serum amyloid protein A (30 μg/l). The genetic panel for autoinflammatory diseases revealed heterozygous mutation in the NLRP3, (c.2068G > C, p.E690Q) with 0% of frequency in the general population. The patient denies rash and did not have frontal bossing or patellar overgrowth. We found a positive familial history on mother and brother, who carried the same mutation. The patient was started on canakinumab which controlled his symptoms. Currently, 241 missense variants in the NLRP3 have been described. We presented a new mutation in exon 3 of the NRLP3 gene in a patient that fulfills clinical criteria for CAPS who had complete clinical response to Canakinumab, supporting the idea that this mutation is pathogenic.

Type I interferon (IFN) is a primary pathogenic factor in systemic lupus erythematosus (SLE). Gain-of-function genetic variants in the type I IFN pathway have been associated with risk of disease. Common polygenic as well as rare monogenic influences on type I IFN have been demonstrated, supporting a complex genetic basis for high IFN in many SLE patients. Both SLE-associated autoantibodies and high type I IFN can be observed in the pre-disease state. Patients with SLE and evidence of high type I IFN have more active disease and a greater propensity to nephritis and other severe manifestations. Despite the well-established association between type I IFN and SLE, the specific triggers of type I IFN production, the mechanisms by which IFNs help perpetuate the cycle of autoreactive cells and autoantibody production are not completely clear. This review provides an updated overview of type I IFN in SLE pathogenesis, clinical manifestations, and current therapeutic strategies targeting this pathway.