Why Do We Need JAK Inhibitors in Systemic Lupus Erythematosus?

PARP7 inhibits type I interferon signaling to prevent autoimmunity and lung disease

Type I IFN (IFN-I) induce hundreds of antiviral genes as well as negative regulators that limit IFN-I signaling. Here, we investigate the family of 16 PARPs and find that 11 PARPs are ISGs, of which 8 PARPs inhibit IFN-I production. PARP7 is the most potent negative feedback regulator of IFN-I production. Using Parp7-/- and Parp7H532A/H532A mice, we show that PARP7 loss leads to systemic autoimmunity characterized by splenomegaly and increased autoantibodies and inflammatory cytokines. PARP7 loss also results in perivascular immune infiltration in the lung that forms tertiary lymphoid structures. Mechanistically, PARP7 inhibits multiple innate immune pathways in a cell-intrinsic and MARylation-dependent manner. PARP7 interacts with IRF3 through the catalytic domain and disrupts the IRF3:CBP/p300 transcriptional holocomplex required for IFN-I production. Irf3-/- or Irf3S1/S1 (transcription defective) or Sting-/- rescues Parp7H532A/H532A mouse autoimmunity and lung disease. Together, our study reveals physiological functions of PARP7 as a negative feedback regulator of IFN-I production that maintains immune homeostasis particularly in the lung.

Intricating connections: the role of ferroptosis in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory and autoimmune disease with multiple tissue damage. However, the pathology remains elusive, and effective treatments are lacking. Multiple types of programmed cell death (PCD) implicated in SLE progression have recently been identified. Although ferroptosis, an iron-dependent form of cell death, has numerous pathophysiological features similar to those of SLE, such as intracellular iron accumulation, mitochondrial dysfunction, lipid metabolism disorders and concentration of damage associated-molecular patterns (DAMPs), only a few reports have demonstrated that ferroptosis is involved in SLE progression and that the role of ferroptosis in SLE pathogenesis continues to be neglected. Therefore, this review elucidates the potential intricate relationship between SLE and ferroptosis to provide a reliable theoretical basis for further research on ferroptosis in the pathogenesis of SLE.

Clinical Practice Mexican Guidelines for the Treatment of Systemic Lupus Erythematosus: 2024 Update

Herein we present the update for the Mexican Guidelines for the Treatment of Systemic Lupus Erythematosus. It involves the participation of several experts along the country, following the GRADE system. We included aspects regarding vaccines, pregnancy and cardiovascular risk which were not presented in the previous guidelines in 2017.

Tofacitinib for child-onset systemic lupus erythematosus

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that can cause diverse clinical manifestations in multiple organ systems. Child-onset SLE (cSLE) is associated with significantly higher morbidity and mortality than adult-onset SLE. The traditional treatments for SLE (glucocorticoids, antimalarials, conventional and biological disease-modifying antirheumatic drugs) often have significant adverse effects and may not fully control disease activity. Tofacitinib is an oral Janus kinase (JAK) inhibitor that inhibits the JAK-STAT pathway and has the potential to reduce SLE severity.

Methods

cSLE patients who received tofacitinib and had at least one follow-up visit were retrospectively examined. Case histories, laboratory test results, and treatment regimens were analyzed at disease onset, initiation of tofacitinib treatment, and 1, 3, 6, 9, 12, 18, and 24 months after starting tofacitinib.

Results

We examined 9 patients with refractory cSLE. All patients were female and the average age at diagnosis was 10.67 years. At initiation of tofacitinib, the average age was 13.28 years and the average disease duration was 2.62 years. Four patients experienced alleviation of symptoms and reduced their daily prednisone dosages; one of them also discontinued cyclosporine A and two of them also discontinued belimumab. The other 5 patients experienced no apparent benefit.

Conclusion

Tofacitinib may provide clinical benefits for some patients with refractory cSLE, and can also allow reduction in the glucocorticoid dosage. Tofacitinib has the potential as an adjunctive treatment for some patients with cSLE.

The effectiveness of ruxolitinib and cyclophosphamide combination on T helper 17 and regulatory T cells in rat experimental membranous glomerulonephritis

The progression and pathogenesis of membranous glomerulonephritis (MGN) are inextricably linked to chronic inflammation. Despite improving clinical remission rates due to the application of cyclophosphamide (CYC), treatment of MGN still requires further exploration. Ruxolitinib (Ruxo) negatively affects the signaling pathways participating in the production of pro-inflammatory cytokines. Hence, we investigated whether the combination of CYC and Ruxo can modulate inflammation through influencing T helper 17 (Th17) lineages and regulatory T cells (Tregs). Passive Heymann nephritis (PHN), an experimental model of MGN, was induced in a population of rats. Then, the animals were divided into five groups: PHN, CYC-receiving, Ruxo-receiving, CYC-Ruxo-receiving PHN rats, and healthy controls. After 28 days of treatment, biochemistry analysis was performed and splenocytes were isolated for flowcytometry investigation of Th17 cells and Tregs. The correlative transcription factors of the cells, alongside their downstream cytokine gene expressions, were also assessed using real-time PCR. Furthermore, serum cytokine signatures for the lymphocytes were determined through ELISA. The combination of CYC and Ruxo significantly reduced the serum values of urea in rats versus the PHN group (24.62 ± 7.970 vs. 40.60 ± 10.81 mg/dL). In contrast to Treg's activities, the functionality of Th17 cells noticeably increased not only in PHN rats but also in CYC or Ruxo-receiving PHN animals when compared with the control (10.60 ± 2.236, 8.800 ± 1.465, 8.680 ± 1.314 vs. 4.420 ± 1.551 %). However, in comparison to the PHN group, the incidence of Th17 cells notably fell in rats receiving CYC and Ruxo (10.60 ± 2.236 vs. 6.000 ± 1.373 %) in favor of the Treg's percentage (5.020 ± 1.761 vs. 8.980 ± 1.178 %), which was verified by the gene expressions and cytokine productions correlative to these lymphocytes. The combination of CYC and Ruxo was able to decline Th17 cells in favor of Tregs improvement in PHN rats, suggesting an innovative combination therapy in MGN treatment approaches.

Tryptophan degradation as a systems phenomenon in inflammation - an analysis across 13 chronic inflammatory diseases

BACKGROUND

Chronic inflammatory diseases (CIDs) are systems disorders that affect diverse organs including the intestine, joints and skin. The essential amino acid tryptophan (Trp) can be broken down to various bioactive derivatives important for immune regulation. Increased Trp catabolism has been observed in some CIDs, so we aimed to characterise the specificity and extent of Trp degradation as a systems phenomenon across CIDs.

METHODS

We used high performance liquid chromatography and targeted mass spectrometry to assess the serum and stool levels of Trp and Trp derivatives. Our retrospective study incorporates both cross-sectional and longitudinal components, as we have included a healthy population as a reference and there are also multiple observations per patient over time.

FINDINGS

We found reduced serum Trp levels across the majority of CIDs, and a prevailing negative relationship between Trp and systemic inflammatory marker C-reactive protein (CRP). Notably, serum Trp was low in several CIDs even in the absence of measurable systemic inflammation. Increases in the kynurenine-to-Trp ratio (Kyn:Trp) suggest that these changes result from increased degradation along the kynurenine pathway.

INTERPRETATION

Increases in Kyn:Trp indicate the kynurenine pathway as a major route for CID-related Trp metabolism disruption and the specificity of the network changes indicates excessive Trp degradation relative to other proteogenic amino acids. Our results suggest that increased Trp catabolism is a common metabolic occurrence in CIDs that may directly affect systemic immunity.

FUNDING

This work was supported by the DFG Cluster of Excellence 2167 "Precision medicine in chronic inflammation" (KA, SSchr, PR, BH, SWa), the BMBF (e:Med Juniorverbund "Try-IBD" 01ZX1915A and 01ZX2215, the e:Med Network iTREAT 01ZX2202A, and GUIDE-IBD 031L0188A), EKFS (2020_EKCS.11, KA), DFG RU5042 (PR, KA), and Innovative Medicines Initiative 2 Joint Undertakings ("Taxonomy, Treatments, Targets and Remission", 831434, "ImmUniverse", 853995, "BIOMAP", 821511).

[Jianpi Zishen granule inhibits podocyte autophagy in systemic lupus erythematosus: a network pharmacology and clinical study]

OBJECTIVE

To explore the therapeutic mechanism of Jianpi Zishen (JPZS) granules for systemic lupus erythematosus(SLE) in light of podocyte autophagy regulation.

METHODS

TCMSP, GeneCards, OMIM, and TTD databases were used to obtain the targets of JPZS granules, SLE, and podocyte autophagy. The protein-protein interaction network was constructed using Cytoscape, and the key active ingredients and targets were screened for molecular docking. In the clinical study, 46 patients with SLE were randomized into two groups to receive baseline treatment with prednisone acetate and mycophenolate mofetil (control group) and additional treatment with JPZS granules (observation group) for 12 weeks, with 10 healthy volunteers as the healthy control group. Urinary levels of nephrin and synaptopodin of the patients were detected with ELISA. Western blotting was performed to determine peripheral blood levels of p-JAK1/JAK1, p-STAT1/STAT1, LC3II/LC3I, and p62 proteins of the participants.

RESULTS

Four key active ingredients and 5 core target genes (STAT1, PIK3CG, MAPK1, PRKCA, and CJA1) were obtained, and enrichment analysis identified the potentially involved signaling pathways including AGE-RAGE, JAK/STAT, EGFR, and PI3K/Akt. Molecular docking analysis showed that STAT1 was the most promising target protein with the highest binding activity, suggesting its role as an important mediator for signal transduction after JPZS granule treatment. In the 43 SLE patients available for analysis, treatment with JPZS granule significantly reduced serum levels of p-JAK1/JAK1, p-STAT1/STAT1, and LC3II/LC3I (P < 0.05 or 0.01), increased the protein level of P62 (P < 0.05), and reduced urinary levels of nephrin and synaptopodin (P < 0.05).

CONCLUSION

The therapeutic effect of JPZS granules on SLE is mediated probably by coordinated actions of quercetin, kaempferol, β-sitosterol, and isorhamnetin on their target gene STAT1 to inhibit the JAK/STAT pathway, thus suppressing autophagy and alleviating podocyte injuries in SLE.

Novel heterozygous TREX1 mutation in a juvenile systemic lupus erythematosus patient with severe cutaneous involvement treated successfully with Jak-inhibitors: a case report

Juvenile systemic lupus erythematosus (jSLE) is a complex inflammatory autoimmune disorder. In the last decades, genetic factors and activation pathways have been increasingly studied to understand their potential pathogenetic role better. Genetic and transcriptional abnormalities directly involved in the type I interferon (IFN) signaling cascade have been identified through family-based and genome-wide association studies. IFNs trigger signaling pathways that initiate gene transcription of IFN-stimulated genes through the activation of JAK1, TYK2, STAT1, and STAT2. Thus, the use of therapies that target the IFN pathway would represent a formidable advance in SLE. It is well known that JAK inhibitors have real potential for the treatment of rheumatic diseases, but their efficacy in the treatment of SLE remains to be elucidated. We report the case of a 13-year-old girl affected by jSLE, carrying a novel heterozygous missense variant on Three prime Repair EXonuclease 1 (TREX1), successfully treated with baricitinib on top of mofetil mycophenolate. The TREX1 gene plays an important role in DNA damage repair, and its mutations have been associated with an overproduction of type 1 interferon. This report underlines the role of translational research in identifying potential pathogenetic pathways in rare diseases to optimize treatment.

From Pathogenesis to Treatment-New Perspectives in Rheumatology

Rheumatic diseases are characterized by complex pathogenic mechanisms, with intricate signaling pathways and various imbalances of proinflammatory and anti-inflammatory cytokines, especially in the case of immune-inflammatory conditions [...].

Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus (jSLE)

Systemic lupus erythematosus (SLE) is a rare autoimmune/inflammatory disease with significant morbidity and mortality. Approximately 15-20% of SLE patients develop the disease during childhood or adolescence (juvenile-onset SLE/jSLE). Patients with jSLE exhibit more variable and severe disease when compared to patients with disease-onset during adulthood. Neuropsychiatric (NP) involvement is a clinically heterogenous and potentially severe complication. Published reports on the incidence and prevalence of NP-jSLE are scarce, and the exact pathophysiology is poorly understood.This manuscript provides a review of the existing literature, suggesting NP involvement in 13.5-51% of jSLE patients. Among patients with NP-jSLE affecting the CNS, we propose two main subgroups: (i) a chronic progressive, predominantly type 1 interferon-driven form that poorly responds to currently used treatments, and (ii) an acutely aggressive form that usually presents early during the disease that may be primarily mediated by auto-reactive effector lymphocytes. While this hypothesis requires to be tested in large collaborative international cohort studies, it may offer future patient stratification and individualised care.

Effects of Dietary Oleacein Treatment on Endothelial Dysfunction and Lupus Nephritis in Balb/C Pristane-Induced Mice

Systemic lupus erythematosus (SLE) is a chronic immune-inflammatory disease characterized by multiorgan affectation and lowered self-tolerance. Additionally, epigenetic changes have been described as playing a pivotal role in SLE. This work aims to assess the effects of oleacein (OLA), one of the main extra virgin olive oil secoiridoids, when used to supplement the diet of a murine pristane-induced SLE model. In the study, 12-week-old female BALB/c mice were injected with pristane and fed with an OLA-enriched diet (0.01 % (w/w)) for 24 weeks. The presence of immune complexes was evaluated by immunohistochemistry and immunofluorescence. Endothelial dysfunction was studied in thoracic aortas. Signaling pathways and oxidative-inflammatory-related mediators were evaluated by Western blotting. Moreover, we studied epigenetic changes such as DNA methyltransferase (DNMT-1) and micro(mi)RNAs expression in renal tissue. Nutritional treatment with OLA reduced the deposition of immune complexes, ameliorating kidney damage. These protective effects could be related to the modulation of mitogen-activated protein kinases, the Janus kinase/signal transducer and transcription activator of transcription, nuclear factor kappa, nuclear-factor-erythroid-2-related factor 2, inflammasome signaling pathways, and the regulation of miRNAs (miRNA-126, miRNA-146a, miRNA-24-3p, and miRNA-123) and DNMT-1 expression. Moreover, the OLA-enriched diet normalized endothelial nitric oxide synthase and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-1 overexpression. These preliminary results suggest that an OLA-supplemented diet could constitute a new alternative nutraceutical therapy in the management of SLE, supporting this compound as a novel epigenetic modulator of the immunoinflammatory response.

Refractory alopecia in lupus treated with tofacitinib - a case-based review

One of the common cutaneous symptoms of systemic lupus erythematosus (SLE) that may have major psychosocial effects in a female is diffuse alopecia. Although Janus kinase inhibitors have shown encouraging results in the treatment of SLE and of alopecia areata in recent studies, tofacitinib in treating refractory alopecia caused by SLE has been rarely documented. The Janus kinases (JAKs) are intracellular tyrosine kinases that play a significant role in the pathophysiology of SLE by participating in a wide range of inflammatory cascades. Here, we reported a 33-year-old SLE patient with long standing (3 years) refractory alopecia who took tofacitinib and observed a substantial increase in hair growth. This was sustained at 2-years follow-up even after tapering off glucocorticoids completely. In addition, we reviewed the literature to look for further evidence to support the use of JAK inhibitors for alopecia in SLE.

Association of the STAT4 Gene rs7574865 Polymorphism with IFN-γ Levels in Patients with Systemic Lupus Erythematosus

STAT4 plays an important role in disease activity in SLE patients. STAT4 particles have the capacity to activate the transcription of genes associated with the production of TH1 and Th17 lymphocytes, with a greater predominance on the production of IFN-γ and IL-17A. The presence of variants in STAT4 genes has a major impact on the generation of autoimmunity. However, there are few studies evaluating the impact of these variants on the production of proinflammatory cytokines such as IFN-γ and IL-17A. Methods—A case–control study was carried out with 206 Mexican mestizo patients residing in Western Mexico with a diagnosis of SLE and a group of 80 patients without autoimmune diseases was captured to determine the cut-off point for high IFN-γ levels. In this study, SLE patients with high IFN-γ levels were considered as cases (cut-off > 15.6 pg/mL), and SLE patients with normal IFN-γ levels were considered as controls (cut-off ≤ 15.6 pg/mL). Disease activity was identified from the systemic lupus erythematosus disease activity index (SLEDAI). For the determination of levels of cytokines IFN-γ, IL-12, and IL17A, commercial ELISA kits were used. Genotyping of STAT4 rs7574865 (G > T) was performed by quantitative polymerase chain reaction (qPCR) using TaqMan probes. Results—The patients with SLE had a median age of 45 years with a range of disease duration from 4 years to 18 years; 45.6% were identified as having disease activity. In this sample, we identified a high IFN-γ prevalence of 35.4%. The levels of IFN-γ were higher in the patients with genotype TT than GG. We found that TT genotype conferred a higher risk of high IFN-γ when compared to the GG and GT genotypes. Conclusions—In this study, we identified that the polymorphic genotype TT of the STAT4 gene rs7574865 polymorphism is associated with increased levels of IFN-γ. However, its strength of association was weak, so complementary studies are needed to evaluate its impact on SLE patients.

Breaking down the cellular responses to type I interferon neurotoxicity in the brain

Since their original discovery, type I interferons (IFN-Is) have been closely associated with antiviral immune responses. However, their biological functions go far beyond this role, with balanced IFN-I activity being critical to maintain cellular and tissue homeostasis. Recent findings have uncovered a darker side of IFN-Is whereby chronically elevated levels induce devastating neuroinflammatory and neurodegenerative pathologies. The underlying causes of these 'interferonopathies' are diverse and include monogenetic syndromes, autoimmune disorders, as well as chronic infections. The prominent involvement of the CNS in these disorders indicates a particular susceptibility of brain cells to IFN-I toxicity. Here we will discuss the current knowledge of how IFN-Is mediate neurotoxicity in the brain by analyzing the cell-type specific responses to IFN-Is in the CNS, and secondly, by exploring the spectrum of neurological disorders arising from increased IFN-Is. Understanding the nature of IFN-I neurotoxicity is a crucial and fundamental step towards development of new therapeutic strategies for interferonopathies.

Potential Use of Janus Kinase Inhibitors in the Treatment of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic, autoimmune disease with unclear pathogenesis. One characteristic of SLE is pro-inflammatory and anti-inflammatory cytokine imbalance. Janus kinase (JAK) is an intracellular non-receptor tyrosine kinase essential for many cytokine signaling pathways. Dysregulation of the JAK/signal transduction and transcriptional activator (STAT) pathway is an important process in SLE pathogenesis. Targeting JAK/STAT proteins can simultaneously block the functions of multiple cytokines. Current SLE treatment with non-specific corticosteroids and immunosuppressants can cause many adverse reactions. Therefore, treatments designed to control specific molecular targets for SLE are desirable. JAK inhibitors (JAKis) are a potential treatment for rheumatic diseases; however, the use of targeted signaling pathways to treat SLE remains a challenge, and its efficacy has not been determined. JAKis have shown positive results in reducing the use of glucocorticoids and/or non-specific immunosuppressants for SLE. JAKis are currently undergoing several clinical trials and expected to be the next stage in the treatment of SLE. Therefore, inhibition of the JAK/STAT pathway through JAKis may improve traditional treatment strategies for SLE.