piperidines and Lupus-Erythematosus--Systemic

This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence-based guideline for the perioperative management of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).. A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi-step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.. The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease-modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low- or moderate-quality evidence.. This guideline should help decision-making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high-quality direct randomized controlled trial data.

Topics: Antirheumatic Agents; Arthritis, Juvenile; Arthritis, Psoriatic; Arthritis, Rheumatoid; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Elective Surgical Procedures; Glucocorticoids; Humans; Lupus Erythematosus, Systemic; Perioperative Care; Piperidines; Pyrimidines; Pyrroles; Rheumatic Diseases; Rheumatology; Spondylarthritis; Spondylitis, Ankylosing; Surgeons; United States

Systemic lupus erythematosus (SLE) is a disabling and deadly disease. Development of novel therapies for SLE has historically been limited by incomplete understanding of immune dysregulation. Recent advances in lupus pathogenesis, however, have led to the adoption or development of new therapeutics, including the first Food and Drug Administration-approved drug in 50 years.. Multiple cytokines (interferon, B lymphocyte stimulator, IL-6, and IL-17), signaling pathways (Bruton's Tyrosine Kinase, Janus kinase/signal transducer and activator of transcription), and immune cells are dysregulated in SLE. In this review, we cover seminal discoveries that demonstrate how this dysregulation is integral to SLE pathogenesis and the novel therapeutics currently under development or in clinical trials. In addition, early work suggests metabolic derangements are another target for disease modification. Finally, molecular profiling has led to improved patient stratification in the heterogeneous SLE population, which may improve clinical trial outcomes and therapeutic selection.. Recent advances in the treatment of SLE have directly resulted from improved understanding of this complicated disease. Rheumatologists may have a variety of novel agents and more precise targeting of select lupus populations in the coming years.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; B-Cell Activating Factor; Cyclic S-Oxides; Cytokines; Drug Approval; Drug Discovery; Humans; Immunologic Factors; Immunosuppressive Agents; Interferon-alpha; Interleukin-17; Interleukin-6; Isoquinolines; Janus Kinases; Lupus Erythematosus, Systemic; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Recombinant Fusion Proteins; Rituximab; Signal Transduction; STAT Transcription Factors

Increased risk of premature cardiovascular disease (CVD) is well recognized in systemic lupus erythematosus (SLE). Aberrant type I-Interferon (IFN)-neutrophil interactions contribute to this enhanced CVD risk. In lupus animal models, the Janus kinase (JAK) inhibitor tofacitinib improves clinical features, immune dysregulation and vascular dysfunction. We conducted a randomized, double-blind, placebo-controlled clinical trial of tofacitinib in SLE subjects (ClinicalTrials.gov NCT02535689). In this study, 30 subjects are randomized to tofacitinib (5 mg twice daily) or placebo in 2:1 block. The primary outcome of this study is safety and tolerability of tofacitinib. The secondary outcomes include clinical response and mechanistic studies. The tofacitinib is found to be safe in SLE meeting study's primary endpoint. We also show that tofacitinib improves cardiometabolic and immunologic parameters associated with the premature atherosclerosis in SLE. Tofacitinib improves high-density lipoprotein cholesterol levels (p = 0.0006, CI 95%: 4.12, 13.32) and particle number (p = 0.0008, CI 95%: 1.58, 5.33); lecithin: cholesterol acyltransferase concentration (p = 0.024, CI 95%: 1.1, -26.5), cholesterol efflux capacity (p = 0.08, CI 95%: -0.01, 0.24), improvements in arterial stiffness and endothelium-dependent vasorelaxation and decrease in type I IFN gene signature, low-density granulocytes and circulating NETs. Some of these improvements are more robust in subjects with STAT4 risk allele.

Topics: Adult; Aged; Animals; Atherosclerosis; Cholesterol, HDL; Double-Blind Method; Female; Genetic Predisposition to Disease; Heart Disease Risk Factors; Humans; Janus Kinase Inhibitors; Lupus Erythematosus, Systemic; Male; Middle Aged; Piperidines; Pyrimidines; STAT4 Transcription Factor; Treatment Outcome; Vascular Stiffness; Vasodilation; Young Adult

Systemic lupus erythematosus (SLE) is a multisystemic, inflammatory autoimmune disease. Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells participated in the pathogenesis of SLE. MDSCs has been considered a potential therapeutic target for lupus. As traditional Chinese medicine, Halofuginone (HF) has the extensive immunomodulatory effects on some autoimmune disorders. Our research was dedicated to discovering therapeutic efficacy of HF for lupus to explore novel mechanisms on MDSCs. We found that HF prominently alleviated the systemic symptoms especially nephritis in Imiquimod-induced lupus mice, and simultaneously repaired the immune system, reflected in the alteration of autoantibodies. HF diminished the quantity of MDSCs in lupus mice, and induced apoptosis of MDSCs. Through RNA sequencing performed on the sorted MDSC from lupus mice and HF-treated lupus mice, B lymphoid tyrosine kinase (Blk, a non-receptor cytoplasmic tyrosine kinase) was screened as the target molecule of HF. It's proven that HF had two independent effects on Blk. On the one hand, HF increased the mRNA expression of Blk in MDSCs by inhibiting the nuclear translocation of p65/p50 heterodimer. On the other hand, HF enhanced the kinase activity of Blk in MDSCs through direct molecular binding. We further investigated that Blk suppressed the phosphorylation of downstream ERK signaling pathway to increase the apoptosis of MDSCs. In conclusion, our study illustrated that HF alleviated the disease progression of lupus mice by targeting Blk to promote the apoptosis of MDSCs, which indicated the immunotherapeutic potential of HF to treat lupus.

Topics: Animals; Lupus Erythematosus, Systemic; Mice; Myeloid-Derived Suppressor Cells; Piperidines; Quinazolinones

Topics: Humans; Lupus Erythematosus, Cutaneous; Lupus Erythematosus, Systemic; Piperidines; Pyrimidines

Topics: Chilblains; Humans; Lupus Erythematosus, Cutaneous; Lupus Erythematosus, Systemic; Piperidines; Pyrimidines

B-cell secretion of autoantibodies drives autoimmune diseases, including systemic lupus erythematosus and idiopathic inflammatory myositis. Few therapies are presently available for treatment of these patients, often resulting in unsatisfactory effects and helping only some of the patients. We developed a screening assay for evaluation of novel targets suspending B-cell maturation into antibody secreting cells, which could contribute to future drug development. The assay was employed for testing 43 high quality chemical probes and compounds inhibiting under-explored protein targets, using primary cells from patients with autoimmune disease. Probes inhibiting bromodomain family proteins and histone methyl transferases demonstrated abrogation of B-cell functions to a degree comparable to a positive control, the JAK inhibitor tofacitinib. Inhibition of each target rendered a specific functional cell and potential disease modifying effect, indicating specific epigenetic protein targets as potential new intervention points for future drug discovery and development efforts.

Topics: Adult; Aged; Autoimmune Diseases; B-Lymphocytes; Case-Control Studies; Cells, Cultured; Cytokines; Epigenesis, Genetic; Female; Humans; Immunoglobulin Isotypes; Leukocytes, Mononuclear; Lupus Erythematosus, Systemic; Male; Middle Aged; Molecular Probes; Myositis, Inclusion Body; Piperidines; Polymyositis; Pyrimidines

Systemic lupus erythematosus is a chronic inflammatory disease, in which treatment is still limited due to suboptimal efficacy and toxicities associated with the available therapies. JAK kinases are well known to play an important role in systemic lupus erythematous. There is growing evidence that ROCK kinases are also important in disease development. In this paper, we present the results of the development of CPL409116, a dual JAK and ROCK inhibitor. The studies we performed demonstrate that this molecule is an effective JAK and ROCK inhibitor which efficiently blocks disease progression in NZBWF1/J mouse models of systemic lupus erythematous.

Topics: Animals; Cells, Cultured; Disease Models, Animal; Disease Progression; Female; Janus Kinase Inhibitors; Janus Kinases; Lupus Erythematosus, Systemic; Mice, Transgenic; Piperidines; Pyrimidines; rho-Associated Kinases; Treatment Outcome

The Janus kinases (JAKs) are intracellular tyrosine kinases involved in a broad variety of inflammatory cascades participating in the pathogenesis of systemic lupus erythematosus (SLE). Diffuse non-scarring alopecia is one of the most frequent cutaneous manifestations in SLE, resulting in devastating psychosocial consequences. Although recent studies have shown promising outcomes of the JAK inhibitors in SLE treatment, the efficacy of tofacitinib in diffuse non-scarring alopecia due to SLE has never been reported. Here we present a 29-year-old SLE patient with a 10-year history of refractory severe diffuse non-scarring alopecia who experienced dramatic hair regrowth with tofacitinib. Furthermore, we have made a systematic review regarding the potential effectiveness of tofacitinib in systemic and cutaneous lupus erythematosus. To the best of our knowledge, this is the first case study depicting an SLE patient with refractory alopecia who experienced impressive hair regrowth with the JAK1/3 inhibitor tofacitinib therapy, which contributes to expanding the field of possible uses of tofacitinib in SLE patients with difficult-to-treat cutaneous involvement, including severe alopecia.

Topics: Adult; Alopecia Areata; Chronic Disease; Female; Humans; Lupus Erythematosus, Systemic; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Recurrence; Treatment Outcome

Systemic lupus erythematosus (SLE) is a chronic multi-system inflammatory disease associated with autoantibody formation. Clinical management of lupus is associated with multiple adverse events. Resveratrol is a phytoalexin with several pharmacological properties. This study aimed to evaluate the combinatorial effect of resveratrol (25 mg/kg and 50 mg/kg) and its bio-enhancer piperine (1/10th dose of resveratrol) on pristane-induced SLE murine model. Mice were injected with 0.5 ml of pristane and after 2 months they were orally dosed with resveratrol combinations for 4 months. Determined by indirect immunofluorescence, resveratrol was unable to abrogate autoantibody formation. The increased IFN-α, IL-6 and TNF-α was mitigated by low dose of resveratrol and piperine (RP-1). None of the doses regulated the increase in nitric oxide. Lipogranulomas associated with injected pristane were not observed after RP-1 and high dose of resveratrol (Res-2) treatment. Lupus mice witnessed IgG and IgM immune complexes by direct immunofluorescence assay and associated histopathological observations in kidneys, liver, lung, spleen and skin. None of the treatment regimens were able to regulate the manifestations observed in spleen and skin. RP-1 and Res-2 proved beneficial in kidney, liver and lungs and were able to ameliorate lupus associated manifestations. Renal manifestations (proteinuria and decreased creatinine in urine) were successfully mitigated by RP-1 and Res-2 and high dose combination of resveratrol and piperine. Oxidative stress (reactive oxygen species by flowcytometry and catalase, superoxide dismutase, glutathione peroxidase, reduced glutathione and lipid peroxidation by biochemical analysis) was evident by pristane injection. These were regulated by different doses of resveratrol alone and in combination with piperine. Hence, resveratrol when used in combination with piperine successfully reduces some measures of morbidity with little or no effect on mortality associated with lupus.

Topics: Alkaloids; Animals; Autoantibodies; Benzodioxoles; Cytokines; Disease Models, Animal; Dose-Response Relationship, Drug; Female; Lupus Erythematosus, Systemic; Mice; Mice, Inbred BALB C; Piperidines; Polyunsaturated Alkamides; Resveratrol; Terpenes; Treatment Outcome

Systemic lupus erythematosus is a multisystem autoimmune disease. Apart from usual treatments, approximately 50% of lupus patients use complementary medicine. Resveratrol is a phytoalexin with various pharmacological properties. We hypothesised that prophylactic treatment with resveratrol may abrogate manifestations in pristane-induced murine model of lupus-like disease and piperine; a bio-enhancer of resveratrol may enhance these properties. The prophylactic effect of resveratrol (25 mg/kg body weight: P-Res) alone and in combination with piperine (2.5 mg/kg body weight: P-RP) were assessed. P-Res and P-RP were equally efficient in mitigating oxidative stress (enzyme activity of catalase, superoxide dismutase, glutathione peroxidase and level of reduced glutathione, lipid peroxidation, and reactive oxygen species). Inflammation is associated with an increase in inflammatory cytokines. IL-6 was decreased by 71.60% with P-Res, and TNF-α was reduced by 59.70% with P-Res and 62.66% with P-RP (p < 0.05). Prevention of renal pathologies was evident by reduction in creatinine level by P-RP (p < 0.05) and abrogation of proteinuria (P-Res and P-RP). P-RP was efficient in restoring histopathology of liver and lungs and decreased immune complexes in lungs. P-Res proved more beneficial by extenuating lipogranulomas, histopathological manifestations in kidney, liver, and lungs, and eliminating immune complexes in liver and lungs. None of the treatments could regulate auto-antibody formation. Resveratrol decreases the susceptibility of developing pathogenesis in murine model of lupus-like disease. The results also conclude that addressing the bioavailability of resveratrol using it in combination with piperine does not prove more efficacious in preventing lupus-associated pathologies than resveratrol alone.

Topics: Alkaloids; Animals; Antioxidants; Benzodioxoles; Cytokines; Disease Models, Animal; Female; Inflammation; Kidney; Lipid Peroxidation; Liver; Lung; Lupus Erythematosus, Systemic; Mice; Mice, Inbred BALB C; Oxidative Stress; Piperidines; Polyunsaturated Alkamides; Resveratrol; Terpenes

Bruton's tyrosine kinase (BTK), a non-receptor tyrosine kinase, is a member of the Tec family of kinases and is essential for B cell receptor (BCR) mediated signaling. BTK also plays a critical role in the downstream signaling pathways for the Fcγ receptor in monocytes, the Fcε receptor in granulocytes, and the RANK receptor in osteoclasts. As a result, pharmacological inhibition of BTK is anticipated to provide an effective strategy for the clinical treatment of autoimmune diseases such as rheumatoid arthritis and lupus. This article will outline the evolution of our strategy to identify a covalent, irreversible inhibitor of BTK that has the intrinsic potency, selectivity, and pharmacokinetic properties necessary to provide a rapid rate of inactivation systemically following a very low dose. With excellent in vivo efficacy and a very desirable tolerability profile, 5a (branebrutinib, BMS-986195) has advanced into clinical studies.

Topics: Agammaglobulinaemia Tyrosine Kinase; Animals; Arthritis, Rheumatoid; Dose-Response Relationship, Drug; Drug Discovery; Humans; Indoles; Inhibitory Concentration 50; Lupus Erythematosus, Systemic; Macaca fascicularis; Mice; Piperidines; Protein Kinase Inhibitors

Topics: Adolescent; Adult; Arthritis; Exanthema; Female; Humans; Lupus Erythematosus, Systemic; Male; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Pyrroles; Treatment Outcome; Young Adult

This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence-based guideline for the perioperative management of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).. A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi-step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.. The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease-modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low- or moderate-quality evidence.. This guideline should help decision-making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high-quality direct randomized controlled trial data.

Topics: Antirheumatic Agents; Arthritis, Juvenile; Arthritis, Psoriatic; Arthritis, Rheumatoid; Arthroplasty, Replacement, Hip; Arthroplasty, Replacement, Knee; Biological Products; Glucocorticoids; Humans; Immunosuppressive Agents; Lupus Erythematosus, Systemic; Orthopedics; Perioperative Care; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Pyrroles; Rheumatic Diseases; Rheumatology; Societies, Medical; Spondylitis, Ankylosing; United States

Dysregulation of innate and adaptive immune responses contributes to the pathogenesis of systemic lupus erythematosus (SLE) and its associated premature vascular damage. No drug to date targets both systemic inflammatory disease and the cardiovascular complications of SLE. Tofacitinib is a JAK inhibitor that blocks signaling downstream of multiple cytokines implicated in lupus pathogenesis. While clinical trials have shown that tofacitinib exhibits significant clinical efficacy in various autoimmune diseases, its role in SLE and the associated vascular pathology remains to be characterized.. MRL/lpr lupus-prone mice were administered tofacitinib or vehicle by gavage for 6 weeks (therapeutic arm) or 8 weeks (preventive arm). Nephritis, skin inflammation, serum levels of autoantibodies and cytokines, mononuclear cell phenotype and gene expression, neutrophil extracellular traps (NETs) release, endothelium-dependent vasorelaxation, and endothelial differentiation were compared in treated and untreated mice.. Treatment with tofacitinib led to significant improvement in measures of disease activity, including nephritis, skin inflammation, and autoantibody production. In addition, tofacitinib treatment reduced serum levels of proinflammatory cytokines and interferon responses in splenocytes and kidney tissue. Tofacitinib also modulated the formation of NETs and significantly increased endothelium-dependent vasorelaxation and endothelial differentiation. The drug was effective in both preventive and therapeutic strategies.. Tofacitinib modulates the innate and adaptive immune responses, ameliorates murine lupus, and improves vascular function. These results indicate that JAK inhibitors have the potential to be beneficial in SLE and its associated vascular damage.

Topics: Animals; Female; Lupus Erythematosus, Systemic; Mice; Mice, Inbred MRL lpr; Piperidines; Protein Kinase Inhibitors; Pyrimidines; Pyrroles; Vascular Diseases

Efficient apoptotic cell clearance and induction of immunologic tolerance is a critical mechanism preventing autoimmunity and associated pathology. Our laboratory has reported that apoptotic cells induce tolerance by a mechanism dependent on the tryptophan catabolizing enzyme indoleamine 2,3 dioxygenase 1 (IDO1) in splenic macrophages (MΦ). The metabolic-stress sensing protein kinase GCN2 is a primary downstream effector of IDO1; thus, we tested its role in apoptotic cell-driven immune suppression. In vitro, expression of IDO1 in MΦs significantly enhanced apoptotic cell-driven IL-10 and suppressed IL-12 production in a GCN2-dependent mechanism. Suppression of IL-12 protein production was due to attenuation of IL-12 mRNA association with polyribosomes inhibiting translation while IL-10 mRNA association with polyribosomes was not affected. In vivo, apoptotic cell challenge drove a rapid, GCN2-dependent stress response in splenic MΦs with increased IL-10 and TGF-β production, whereas myeloid-specific deletion of GCN2 abrogated regulatory cytokine production with provocation of inflammatory T-cell responses to apoptotic cell antigens and failure of long-tolerance induction. Consistent with a role in prevention of apoptotic cell driven autoreactivity, myeloid deletion of GCN2 in lupus-prone mice resulted in increased immune cell activation, humoral autoimmunity, renal pathology, and mortality. In contrast, activation of GCN2 with an agonist significantly reduced anti-DNA autoantibodies and protected mice from disease. Thus, this study implicates a key role for GCN2 signals in regulating the tolerogenic response to apoptotic cells and limiting autoimmunity.

Topics: Amino Acids; Animals; Apoptosis; Autoimmunity; Cells, Cultured; Cytokines; Disease Models, Animal; Gene Expression Regulation; Immune Tolerance; Indoleamine-Pyrrole 2,3,-Dioxygenase; Inflammation; Lupus Erythematosus, Systemic; Macrophages; Mice; Mice, Inbred C57BL; Mice, Knockout; Myeloid Cells; Piperidines; Protein Serine-Threonine Kinases; Quinazolinones; Signal Transduction

The possibility that drug-induced lupus erythematosus (DILE) can be induced by donepezil is presented in this clinical case. Donepezil is an inhibitor of acetylcholinesterase used for the treatment of Alzheimer's disease. It is the first time that donepezil causes DILE.

Topics: Aged, 80 and over; Alzheimer Disease; Donepezil; Female; Humans; Hydrolases; Indans; Lupus Erythematosus, Systemic; Nootropic Agents; Piperidines; Skin

Autoantibody production and immune complex deposition within the kidney promote renal disease in patients with lupus nephritis. Thus, therapeutics that inhibit these pathways may be efficacious in the treatment of systemic lupus erythematosus. Bruton's tyrosine kinase (BTK) is a critical signaling component of both BCR and FcR signaling. We sought to assess the efficacy of inhibiting BTK in the development of lupus-like disease, and in this article describe (R)-5-amino-1-(1-cyanopiperidin-3-yl)-3-(4-[2,4-difluorophenoxy]phenyl)-1H-pyrazole-4-carboxamide (PF-06250112), a novel highly selective and potent BTK inhibitor. We demonstrate in vitro that PF-06250112 inhibits both BCR-mediated signaling and proliferation, as well as FcR-mediated activation. To assess the therapeutic impact of BTK inhibition, we treated aged NZBxW_F1 mice with PF-06250112 and demonstrate that PF-06250112 significantly limits the spontaneous accumulation of splenic germinal center B cells and plasma cells. Correspondingly, anti-dsDNA and autoantibody levels were reduced in a dose-dependent manner. Moreover, administration of PF-06250112 prevented the development of proteinuria and improved glomerular pathology scores in all treatment groups. Strikingly, this therapeutic effect could occur with only a modest reduction observed in anti-dsDNA titers, implying a critical role for BTK signaling in disease pathogenesis beyond inhibition of autoantibody production. We subsequently demonstrate that PF-06250112 prevents proteinuria in an FcR-dependent, Ab-mediated model of glomerulonephritis. Importantly, these results highlight that BTK inhibition potently limits the development of glomerulonephritis by impacting both cell- and effector molecule-mediated pathways. These data provide support for evaluating the efficacy of BTK inhibition in systemic lupus erythematosus patients.

Topics: Agammaglobulinaemia Tyrosine Kinase; Animals; B-Lymphocytes; Cell Proliferation; Disease Models, Animal; Female; Germinal Center; Glomerulonephritis; Kidney; Lupus Erythematosus, Systemic; Lymphocyte Activation; Mice; Mice, Inbred NZB; Piperidines; Plasma Cells; Protein-Tyrosine Kinases; Pyrazoles; Receptors, Fc; Signal Transduction; T-Lymphocytes

On antigen binding by the B-cell receptor (BCR), B cells up-regulate protein expression of the key downstream signaling molecule Bruton tyrosine kinase (Btk), but the effects of Btk up-regulation on B-cell function are unknown. Here, we show that transgenic mice overexpressing Btk specifically in B cells spontaneously formed germinal centers and manifested increased plasma cell numbers, leading to antinuclear autoantibody production and systemic lupus erythematosus (SLE)-like autoimmune pathology affecting kidneys, lungs, and salivary glands. Autoimmunity was fully dependent on Btk kinase activity, because Btk inhibitor treatment (PCI-32765) could normalize B-cell activation and differentiation, and because autoantibodies were absent in Btk transgenic mice overexpressing a kinase inactive Btk mutant. B cells overexpressing wild-type Btk were selectively hyperresponsive to BCR stimulation and showed enhanced Ca(2+) influx, nuclear factor (NF)-κB activation, resistance to Fas-mediated apoptosis, and defective elimination of selfreactive B cells in vivo. These findings unravel a crucial role for Btk in setting the threshold for B-cell activation and counterselection of autoreactive B cells, making Btk an attractive therapeutic target in systemic autoimmune disease such as SLE. The finding of in vivo pathology associated with Btk overexpression may have important implications for the development of gene therapy strategies for X-linked agammaglobulinemia, the immunodeficiency associated with mutations in BTK.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Autoimmunity; B-Lymphocytes; Cell Lineage; Gene Expression; Germinal Center; Lupus Erythematosus, Systemic; Lymphocyte Activation; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Transgenic; Myeloid Cells; Piperidines; Plasma Cells; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines

Systemic lupus erythematosus is a chronic autoimmune disease characterized by an abundance of autoantibodies against nuclear antigens. Bruton's tyrosine kinase (Btk) is a proximal transducer of the BCR signal that allows for B-cell activation and differentiation. Recently, selective inhibition of Btk by PCI-32765 has shown promise in limiting activity of multiple cells types in various models of cancer and autoimmunity. The aim of this study was to determine the effect of Btk inhibition by PCI-32765 on the development of lupus in lupus-prone B6.Sle1 and B6.Sle1.Sle3 mice.. B6.Sle1 or B6.Sle1.Sle3 mice received drinking water containing either the Btk inhibitor PCI-32765 or vehicle for 56 days. Following treatment, mice were examined for clinical and pathological characteristics of lupus. The effect of PCI-32765 on specific cell types was also investigated.. In this study, we report that Btk inhibition dampens humoral autoimmunity in B6.Sle1 monocongenic mice. Moreover, in B6.Sle1.Sle3 bicongenic mice that are prone to severe lupus, Btk inhibition also dampens humoral and cellular autoimmunity, as well as lupus nephritis.. These findings suggest that partial crippling of cell signaling in B cells and antigen presenting cells (APCs) may be a viable alternative to total depletion of these cells as a therapeutic modality for lupus.

Topics: Adenine; Agammaglobulinaemia Tyrosine Kinase; Animals; Autoantibodies; Autoimmunity; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Kidney; Lupus Erythematosus, Systemic; Lupus Nephritis; Lymphocytes; Male; Mice, Congenic; Mice, Inbred C57BL; Piperidines; Protein-Tyrosine Kinases; Pyrazoles; Pyrimidines; Signal Transduction; Splenomegaly; Treatment Outcome