Cadherin-11 targeted cell-specific liposomes enabled skin fibrosis treatment by inducing apoptosis.

Continuous and aberrant activation of myofibroblasts is the hallmark of pathological fibrosis (e.g., abnormal wound healing). The deposition of excessive extracellular matrix (ECM) components alters or increases the stiffness of tissue and primarily accounts for multiple organ dysfunctions. Among various proteins, Cadherin-11 (CDH11) has been reported to be overexpressed on myofibroblasts in fibrotic tissues. Anti-apoptotic proteins such as (B cell lymphoma-2) (BCL-2) are also upregulated on myofibroblasts. Therefore, we hypothesize that CDH11 could be a targeted domain for cell-specific drug delivery and targeted inhibition of BCL-2 to ameliorate the development of fibrosis in the skin. To prove our hypothesis, we have developed liposomes (LPS) conjugated with CDH11 neutralizing antibody (antiCDH11) to target cell surface CDH11 and loaded these LPS with a BCL-2 inhibitor, Navitoclax (NAVI), to induce apoptosis of CDH11 expressing fibroblasts. The developed LPS were evaluated for physicochemical characterization, stability, in vitro therapeutic efficacy using dermal fibroblasts, and in vivo therapeutic efficacy in bleomycin-induced skin fibrosis model in mice. The findings from in vitro and in vivo studies confirmed that selectivity of LPS was improved towards CDH11 expressing myofibroblasts, thereby improving therapeutic efficacy with no indication of adverse effects. Hence, this novel research work represents a versatile LPS strategy that exhibits promising potential for treating skin fibrosis.

Factors associated with adherence of cervical cancer screening in women with Systemic Lupus Erythematosus.

OBJECTIVES: To determine cervical cancer screening rates and factors associated with decreased cervical cancer screening in women with systemic lupus erythematosus (SLE). METHODS: We conducted a cross-sectional study that enrolled consecutive women (aged 21-64) with SLE. We collected demographics, clinical characteristics, constructs of the Health Beliefs Model (HBM) (i.e., susceptibility, severity, barriers, benefits, cues to action, and self-efficacy), and self-reported cervical cancer screening (confirmed with the electronic medical record). The primary outcome was adherence to cervical cancer screening according to current guidelines. Multivariable logistic regression models were used to examine the association between SLE disease activity and cervical cancer screening, and explore mediation effects from HBM constructs. RESULTS: We enrolled 130 women with SLE. The median age was 42 (IQR 32-52). The cervical cancer screening adherence rate was 61.5%. Women with high SLE disease activity were less likely to have cervical cancer screening versus those with low disease activity (OR 0.59, 0.39-0.89, p=0.01), which remained statistically significant after adjusting for baseline demographics and drug therapy in a multivariable model (OR 0.25, 95% CI 0.08-0.79, p=0.02). Regarding the HBM constructs, increased perceived barriers to cervical cancer screening (r=-0.30, p < 0.01) and decreased self-efficacy (r=-0.21, p=0.02) correlated with decreased cervical cancer screening. CONCLUSION: SLE patients with high disease activity undergo cervical cancer screening less frequently than those with low disease activated. Perceived barriers to cervical cancer screening are moderately correlated with decreased screening. These data highlight to need to develop strategies to increase cervical cancer screening in this high-risk patient population.

CADHERIN-11 regulation of myeloid phagocytes and autoimmune inflammation in murine lupus.

BACKGROUND AND OBJECTIVE: Understanding the regulation of efferocytosis by myeloid phagocytes is important in identifying novel targets in systemic lupus erythematosus (SLE). Cadherin-11 (CDH11), a cell adhesion molecule, is implicated in inflammatory arthritis and fibrosis and recently been shown to regulate macrophage phagocytosis. The extent and mechanism of this regulation is unknown. Our objective was to examine the extent to which CDH11 regulates myeloid phagocytes and contributes to autoimmunity and tissue inflammation. METHODS: We analyzed efferocytosis in macrophages and dendritic cells (DCs) from WT and Cdh11-/- mice and investigated the mechanisms in vitro. We investigated the role of CDH11 in disease development in vivo using the pristane induced lupus model. To translate the clinical relevance of CDH11 in human disease, we measured serum CDH11 levels in two independent pediatric SLE (pSLE) cohorts and healthy controls. RESULTS: Using bone marrow derived macrophages (BMDMs) and DCs (BMDCs), we found impaired efferocytosis in phagocytes from Cdh11-/- mice, mediated by downregulated efferocytosis receptor expression and RhoGTPase activation. Specifically, loss of CDH11 downregulated Mertk expression and Rac1 activation in BMDMs, and integrin αVß3 expression and Cdc42 activation in BMDCs, highlighting distinct pathways. In vivo, Cdh11-/- mice displayed defective efferocytosis and increased accumulation of apoptotic debris in pristane-induced lupus. Further, Cdh11-/- mice had enhanced systemic inflammation and autoimmune inflammation with increased anti-dsDNA autoantibodies, splenomegaly, type I interferons, and inflammatory cytokines. Paradoxically, at the tissue level, Cdh11-/- mice were protected against glomerulonephritis, indicating a dual role in murine lupus. Finally, SLE patients had increased serum CDH11 compared to controls. CONCLUSION: This study highlights a novel role of CDH11 in regulating myeloid cells and efferocytosis and its potential as a contributor to development in autoimmunity murine lupus. Despite the increase in autoimmunity, Cdh11-/- mice developed decreased tissue inflammation and damage.

Risk of incident cardiovascular events with disease-modifying anti-rheumatic drugs among adults with rheumatoid arthritis: a nested case-control study.

OBJECTIVE: This study examined the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA). METHOD: This nested case-control study used the MarketScan database (2012-2014), involving adult RA patients (aged ≥18 years) initiating either a conventional synthetic (cs) DMARD, biologic DMARD, or targeted synthetic (ts) DMARD between January 1, 2013 and December 31, 2014 (cohort entry) and had no CVD history. Cases were individuals with incident CVD identified using diagnosis codes or procedure codes from medical claims. For each case, 10 age- and sex-matched controls were selected using the incident density sampling with replacement. Prescriptions of DMARDs were measured 90 days before the event date. Conditional logistic regression examined the association of risk of CVD with DMARDs in combination treatment or individual use, with reference to methotrexate (MTX) monotherapy, adjusting for baseline confounders. Subgroup analyses were performed separately in DMARD combination therapy users or individual DMARD users, respectively. RESULTS: In total, 270 cases of incident CVD and 2700 controls were included (mean [standard deviation (SD)] age: 54 [1]; 75.6% women). The commonly prescribed DMARD therapies were csDMARD monotherapy (n = 795, 27.04%), followed by  tumor necrosis factor inhibitors (TNFi) monotherapy (n = 367, 12.48%), and TNFi in combination with MTX (n = 314, 10.68%). Compared with MTX monotherapy, overall use of DMARD agents was not associated with the differential risk of CVD, including various types of DMARD combination regimens. The findings were similar across subgroup analyses. CONCLUSIONS: The study found no differential risk of CVD with DMARDs in combination therapy or monotherapy compared to MTX monotherapy in patients with RA. Key Points • This study evaluated the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA). • Findings suggest no differential CVD risk with DMARDs in combination with MTX or used individually compared with MTX monotherapy in patients with early RA. • Further efforts should focus on a better understanding of the mechanism of DMARD combination treatments with MTX in modifying CV risk.

Real-world Comparative Effectiveness of Methotrexate-based Combinations for Rheumatoid Arthritis: A Retrospective Cohort Study.

PURPOSE: Guidelines recommend using disease-modifying antirheumatic drugs (DMARDs) in combination with methotrexate (MTX) for patients with rheumatoid arthritis (RA) after monotherapy. Little is known about the real-world comparative effectiveness of these MTX-DMARD combinations. This study compared the effectiveness of various MTX-based DMARD combinations for patients with RA initiating MTX-DMARD combination therapy using administrative claims database. METHODS: This retrospective cohort study included adults (aged ≥18 years) with RA who initiated MTX combination treatment with conventional synthetic DMARDs (csDMARDs), tumor necrosis factor inhibitor (TNFi) biologic DMARDs (bDMARDs), non-TNFi bDMARDs, or targeted synthetic DMARDs (tsDMARDs) between July 1, 2012, and December 31, 2013 (index date), from the MarketScan Commercial Claims Data. Patients had continuous enrollment from the 6 months of preindex period until the 12 months of postindex period. The MTX-based DMARD combination therapy cohort was defined as ≥1 MTX prescription in the first 30 days from the index date and ≥14 days overlapping use of the prescription fills of the MTX and the index DMARD. Effectiveness was measured by using the claims algorithm (dosing, switching, addition, oral glucocorticoid use, or multiple glucocorticoid injection). Propensity score analysis with the inverse probability of treatment weighting (PS-IPTW), estimated by using the generalized boosted machine learning method, was used to balance the distribution of baseline variables between the combination groups. Multivariable logistic regression using PS-IPTW was conducted to compare the effectiveness of the combination groups. Sensitivity analysis evaluated the modified effectiveness algorithms or the time to the first treatment failure. FINDINGS: A total of 3174 adult patients with RA starting an MTX-DMARD combination therapy were identified (mean [SD] age, 50 [9] years), including 1568 (49%) initiating a csDMARD + MTX, 1343 (42%) initiating TNFi + MTX, and 240 (8%) initiating non-TNFi bDMARD + MTX, and 23 (1%) initiating tsDMARD + MTX. Owing to the small sample, the tsDMARD combination group was not included in the comparative analysis. Algorithm-based therapy effectiveness was found in 9.95% of the csDMARD + MTX, 20.48% of the TNFi + MTX, and 20.83% of the non-TNFi + MTX groups. PS-IPTW showed that the csDMARD combination is less effective (adjusted odds ratio, 0.422; 95% CI, 0.341-0.524) than the TNFi combination; however, the non-TNFi biologic combination had similar effectiveness (aOR, 1.063; 95% CI, 0.680-1.662) compared to the TNFi combination. Sensitivity analyses confirmed the main results. IMPLICATIONS: Among RA patients initiating MTX-DMARD combinations, both non-TNFi biologics and TNFi-based combinations with MTX were equally effective, but csDMARD + MTX was less effective than the TNFi plus MTX.

Factors influencing prescribing the first add-on disease-modifying antirheumatic drugs in patients initiating methotrexate for rheumatoid arthritis.

Background: Advances in Disease-Modifying Antirheumatic Drugs (DMARDs) have expanded the treatment landscape for Rheumatoid Arthritis (RA). Guidelines recommend adding either conventional synthetic (cs), biologic (b), or targeted synthetic (ts) DMARDs to methotrexate (MTX) for managing RA. Limited evidence exists regarding the factors that contribute to adding a DMARD agent to the MTX regimen. This study examined the factors associated with adding the first DMARD in RA patients initiating MTX. Methods: This retrospective cohort study utilized the MarketScan data (2012-2014) involving adults (aged ≥18) with RA initiating an MTX (index date) between Jul 1, 2012 and Dec 30, 2013, and with continuous enrollment for the 6-month pre-index period. The combination therapy users received the first treatment addition of DMARD starting from day 30 after the index MTX over one year period. The study focused on the addition of csDMARDs, Tumor Necrosis Factor Inhibitors (TNFi) bDMARDs, non-TNFi bDMARDs, or tsDMARDs. Baseline covariates were measured in the 6-month pre-index and grouped into predisposing, enabling, and need factors, as per the Andersen Behavior Model. Multivariable logistic regression examined the factors associated with the addition of TNFi compared to adding a csDMARD. An additional regression model evaluated the factors associated with adding any biologic (combining TNFi and non-TNFi biologics). Results: Among 8350 RA patients starting MTX, 31.92% (n = 2665) initiated any DMARD within the 1-year post-index period. Among RA patients initiating a DMARD prescription after starting MTX, 945 (11.32%) received combination therapy with treatment addition of a DMARD to MTX regimen; majority added TNFi (550, 58%), followed by csDMARD (352, 37%); non-TNF biologic (40, 4%), or tsDMARD (3, 0.3%). The tsDMARD group was limited and was not included for further analysis. The multivariable model found Preferred Provider Organization insurance coverage (odds ratio [OR], 1.43; 95% confidence interval (CI), 1.06-1.93), chronic pulmonary disease (OR, 1.98; 95% CI, 1.14-3.44), liver disease (OR, 5.24; 95% CI, 1.77-15.49), and Elixhauser score (OR, 0.91; 95% CI, 0.86-0.97) were significantly associated with the addition of TNF-α inhibitors. The separate multivariable model additionally found that patients from metropolitan areas (OR, 1.50; 95% CI, 1.04-2.16) were positively associated with adding any biological agent. Conclusions: TNFi are often added to MTX for managing RA. Enabling and need factors contribute to the prescribing of a TNFi add-on therapy in RA. Future research should examine the impact of these combination therapies on RA management.

Topical Administration of an Apoptosis Inducer Mitigates Bleomycin-Induced Skin Fibrosis.

Pathological fibrosis is distinguished from physiological wound healing by persistent myofibroblast activation, suggesting that therapies that induce myofibroblast apoptosis selectively could prevent progression and potentially reverse the established fibrosis, such as for scleroderma (a heterogeneous autoimmune disease characterized by multiorgan fibrosis). Navitoclax (NAVI) is a BCL-2/BCL-xL inhibitor with antifibrotic properties and has been investigated as a potential therapeutic for fibrosis. NAVI makes myofibroblasts particularly vulnerable to apoptosis. However, despite NAVI's significant potency, clinical translation of BCL-2 inhibitors, NAVI in this case, is hindered due to the risk of thrombocytopenia. Therefore, in this work, we utilized a newly developed ionic liquid formulation of NAVI for direct topical application to the skin, thereby avoiding systemic circulation and off-target-mediated side effects. The ionic liquid composed of choline and octanoic acid (COA) at a 1:2 molar ionic ratio increases skin diffusion and transportation of NAVI and maintains their retention within the dermis for a prolonged duration. Topical administration of NAVI-mediated BCL-xL and BCL-2 inhibition results in the transition of myofibroblast to fibroblast and ameliorates pre-existing fibrosis, as demonstrated in a scleroderma mouse model. We have observed a significant reduction of α-SMA and collagen, which are known as fibrosis marker proteins, as a result of the inhibition of anti-apoptotic proteins BCL-2/BCL-xL. Overall, our findings show that COA-assisted topical delivery of NAVI upregulates apoptosis specific to myofibroblasts, with minimal presence of the drug in the systemic circulation, resulting in an accelerated therapeutic effect with no discernible drug-associated toxicity.

Immunosuppression for the treatment of pulmonary hypertension in patients with systemic lupus erythematosus: A systematic review.

PURPOSE: To conduct a systematic review with meta-analysis to determine the effects of immunosuppression on Group 1 Pulmonary Arterial Hypertension in patients with systemic lupus erythematosus (SLE). METHODS: We searched Medline, Embase, Web of Science, Clinicaltrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL) with a search strategy developed by a medical librarian. We included retrospective, cross-sectional, case-control, prospective studies, and randomized controlled trials (RCTs) in our analysis and only included studies that contained data for patients with SLE. We included any immunosuppressive agents (including but not limited to cyclophosphamide, glucocorticoids, mycophenolate mofetil, azathioprine, and rituximab) We assessed for risk of bias and certainty of evidence. Outcomes included hemodynamics (as measured by pulmonary arterial hypertension), functional status, 6 minute walk test (6MWT), quality of life, mortality, and serious adverse events. RESULTS: We included three studies. One RCT and two single-arm interventional observational studies. The RCT had a high risk of bias whereas the two single-arm interventional studies were graded as fair quality. Meta-analysis could not be conducted because of insufficient data. The RCT showed significant improvements in hemodynamics (as measured by pulmonary arterial pressures) and functional status. One observational study showed improvements in hemodynamics, functional status, and 6MWT. There were insufficient data for serious adverse events, mortality, and quality of life. CONCLUSIONS: Despite a high prevalence and with a poor prognosis, there is a paucity of data for the role of immunosuppression in the treatment of Group 1 Pulmonary Arterial Hypertension in SLE. More high-quality studies are needed, especially to investigate serious adverse events and quality of life.

IL17A Blockade with Ixekizumab Suppresses MuvB Signaling in Clinical Psoriasis.

Unbiased informatics approaches have the potential to generate insights into uncharacterized signaling pathways in human disease. In this study, we generated longitudinal transcriptomic profiles of plaque psoriasis lesions from patients enrolled in a clinical trial of the anti-IL17A antibody ixekizumab (IXE). This dataset was then computed against a curated matrix of over 700 million data points derived from published psoriasis and signaling node perturbation transcriptomic and chromatin immunoprecipitation-sequencing datasets. We observed substantive enrichment within both psoriasis-induced and IXE-repressed gene sets of transcriptional targets of members of the MuvB complex, a master regulator of the mitotic cell cycle. These gene sets were similarly enriched for pathways involved in the regulation of the G2/M transition of the cell cycle. Moreover, transcriptional targets for MuvB nodes were strongly enriched within IXE-repressed genes whose expression levels correlated strongly with the extent and severity of the psoriatic disease. In models of human keratinocyte proliferation, genes encoding MuvB nodes were transcriptionally repressed by IXE, and depletion of MuvB nodes reduced cell proliferation. Finally, we made the expression and regulatory networks that supported this study available as a freely accessible, cloud-based hypothesis generation platform. Our study positions inhibition of MuvB signaling as an important determinant of the therapeutic impact of IXE in psoriasis.

Oral delivery of RNAi for cancer therapy.

Cancer is a major health concern worldwide and is still in a continuous surge of seeking for effective treatments. Since the discovery of RNAi and their mechanism of action, it has shown promises in targeted therapy for various diseases including cancer. The ability of RNAi to selectively silence the carcinogenic gene makes them ideal as cancer therapeutics. Oral delivery is the ideal route of administration of drug administration because of its patients' compliance and convenience. However, orally administered RNAi, for instance, siRNA, must cross various extracellular and intracellular biological barriers before it reaches the site of action. It is very challenging and important to keep the siRNA stable until they reach to the targeted site. Harsh pH, thick mucus layer, and nuclease enzyme prevent siRNA to diffuse through the intestinal wall and thereby induce a therapeutic effect. After entering the cell, siRNA is subjected to lysosomal degradation. Over the years, various approaches have been taken into consideration to overcome these challenges for oral RNAi delivery. Therefore, understanding the challenges and recent development is crucial to offer a novel and advanced approach for oral RNAi delivery. Herein, we have summarized the delivery strategies for oral delivery RNAi and recent advancement towards the preclinical stages.

Cadherin-11 and Its Role in Tissue Fibrosis.

Fibrosis is the excessive deposition of extracellular matrix that results from chronic inflammation and injury, leading to the loss of tissue integrity and function. Cadherins are important adhesion molecules that classically mediate calcium-dependent cell-to-cell adhesion and play important roles in tissue development and cellular migration but likely have functions beyond these important roles. Cadherin-11 (CDH11), a member of the cadherin family, has been implicated in several pathological processes including cancer. More recent evidence suggests that CDH11 is a central mediator of tissue fibrosis. CDH11 expression is increased in patients with fibrotic diseases such as idiopathic pulmonary fibrosis and systemic sclerosis. CDH11 expression is increased in mouse models of lung, skin, liver, cardiac, renal, and intestinal fibrosis. Targeting CDH11 in murine models of fibrosis clearly demonstrates that CDH11 is a common mediator of fibrosis across multiple tissues. Insight into potential mechanisms at the cellular and molecular level is emerging. In this review, we present the evolving evidence for the involvement of CDH11 in tissue fibrosis. We also discuss some of the proposed mechanisms and highlight the potential of CDH11 as a common therapeutic target and biomarker in different fibrotic pathologies.

Retinoic Acid Receptor Activation Reduces Metastatic Prostate Cancer Bone Lesions by Blocking the Endothelial-to-Osteoblast Transition.

Metastatic prostate cancer in the bone induces bone-forming lesions that contribute to progression and therapy resistance. Prostate cancer-induced bone formation originates from endothelial cells (EC) that have undergone endothelial-to-osteoblast (EC-to-OSB) transition in response to tumor-secreted BMP4. Current strategies targeting prostate cancer-induced bone formation are lacking. Here, we show that activation of retinoic acid receptor (RAR) inhibits EC-to-OSB transition and reduces prostate cancer-induced bone formation. Treatment with palovarotene, an RARγ agonist being tested for heterotopic ossification in fibrodysplasia ossificans progressiva, inhibited EC-to-OSB transition and osteoblast mineralization in vitro and decreased tumor-induced bone formation and tumor growth in several osteogenic prostate cancer models, and similar effects were observed with the pan-RAR agonist all-trans-retinoic acid (ATRA). Knockdown of RARα, ß, or γ isoforms in ECs blocked BMP4-induced EC-to-OSB transition and osteoblast mineralization, indicating a role for all three isoforms in prostate cancer-induced bone formation. Furthermore, treatment with palovarotene or ATRA reduced plasma Tenascin C, a factor secreted from EC-OSB cells, which may be used to monitor treatment response. Mechanistically, BMP4-activated pSmad1 formed a complex with RAR in the nucleus of ECs to activate EC-to-OSB transition. RAR activation by palovarotene or ATRA caused pSmad1 degradation by recruiting the E3-ubiquitin ligase Smad ubiquitination regulatory factor1 (Smurf1) to the nuclear pSmad1/RARγ complex, thus blocking EC-to-OSB transition. Collectively, these findings suggest that palovarotene can be repurposed to target prostate cancer-induced bone formation to improve clinical outcomes for patients with bone metastasis. SIGNIFICANCE: This study provides mechanistic insights into how RAR agonists suppress prostate cancer-induced bone formation and offers a rationale for developing RAR agonists for prostate cancer bone metastasis therapy. See related commentary by Bhowmick and Bhowmick, p. 2975.

The utility of erythrocyte sedimentation rate, C-reactive protein, and procalcitonin in detecting infections in patients with systemic lupus erythematosus: A systematic review.

OBJECTIVES: We conducted a systematic review with metanalysis to investigate the utility of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) in diagnosing infections in hospitalized patients with SLE. METHODS: We searched Medline, Embase, Web of Science, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL) with a search strategy developed by a medical librarian. We included retrospective, cross-sectional, case-control, and prospective studies in our analysis. We used the Quality Assessment of Diagnostic Studies (QUADAS-2) to assess for bias and applicability. We obtained mean differences, sensitivities, and specificities in our analysis. RESULTS: We included 26 studies in our analysis. Most studies had an unclear or high risk of bias and our results were widely heterogenous. For the diagnosis of infections, the CRP had a pooled sensitivity of 0.75 (95%CI 0.57-0.94) and specificity of 0.72 (0.59-0.85), PCT had a pooled sensitivity of 0.68 (95% CI 0.0.59-0.77) and specificity of 0.75 (0.59-0.90), and for ESR pooled estimates were not calculated but sensitivity ranged from 50 to 69.8 and specificity from 38.5 to 55.6. Modifying cut-offs improved sensitivities and specificities. The ESR, CRP, and PCT mean differences were all greater in infection groups versus non-infection (10.1, 95% CI 3.2-17.0; 46.8, 95% CI 36.5-57.0; 0.53, 95% CI 0.26-0.80; respectively). DISCUSSION: Poor sensitivities and specificities were observed for the evaluated biomarkers with substantial heterogeneity in the cut-offs used to determine infection. Although mean biomarker values were increased in the infection group compared with the non-infection, our findings do not support the widespread use of ESR, CRP, or PCT in diagnosing infection in hospitalized patients with SLE due to increased heterogeneity and risk of bias. Further investigation is needed.

Cadherin-11 Regulates Macrophage Development and Function.

Cadherin-11 (CDH11) is a cell-cell adhesion protein that has previously been reported to play an important role in the pathogenesis of pulmonary fibrosis. It is expressed on macrophages in the fibrotic lung. However, the role of CDH11 on macrophage biology has not yet been studied. We show using immunophenotypic analyses that Cdh11-/- mice have fewer recruited monocyte-derived macrophages and Ly6Chi monocytes in the lungs compared to wild-type mice in the intraperitoneal bleomycin-induced pulmonary fibrosis model. Additionally, fewer Ly6Chi monocytes were detected in the bone marrow and peripheral blood of naive Cdh11-/- mice. Given that macrophages are derived from monocytes, we investigated the precursors of the monocyte/macrophage lineage in the bone marrow. We found increased numbers of CMPs and reduced numbers of GMPs and MPs/cMoPs in Cdh11-/- mice compared to wild-type mice, suggesting decreased differentiation towards the myeloid lineage in Cdh11-/- mice. Furthermore, we show using bone marrow cells that loss of CDH11 impaired monocyte to macrophage differentiation. We also demonstrate that CDH11 deficiency repressed the M2 program and impaired the phagocytic function of bone marrow-derived macrophages. Overall, our findings demonstrate a role for CDH11 in macrophage development, M2 polarization, and phagocytic function.

Targeting type I interferons in systemic lupus erythematous.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease with systemic clinical manifestations including, but not limited to, rash, inflammatory arthritis, serositis, glomerulonephritis, and cerebritis. Treatment options for SLE are expanding and the increase in our understanding of the immune pathogenesis is leading to the development of new therapeutics. Autoantibody formation and immune complex formation are important mediators in lupus pathogenesis, but an important role of the type I interferon (IFN) pathway has been identified in SLE patients and mouse models of lupus. These studies have led to the development of therapeutics targeting type I IFN and related pathways for the treatment of certain manifestations of SLE. In the current narrative review, we will discuss the role of type I IFN in SLE pathogenesis and the potential translation of these data into strategies using type I IFN as a biomarker and therapeutic target for patients with SLE.

A highly potent lymphatic system-targeting nanoparticle cyclosporine prevents glomerulonephritis in mouse model of lupus.

Cyclosporine A (CsA) is a powerful immunosuppressant, but it is an ineffective stand-alone treatment for systemic lupus erythematosus (SLE) due to poor target tissue distribution and renal toxicity. We hypothesized that CD71 (transferrin receptor 1)-directed delivery of CsA to the lymphatic system would improve SLE outcomes in a murine model. We synthesized biodegradable, ligand-conjugated nanoparticles [P2Ns-gambogic acid (GA)] targeting CD71. GA conjugation substantially increased nanoparticle association with CD3+ or CD20+ lymphocytes and with intestinal lymphoid tissues. In orally dosed MRL-lpr mice, P2Ns-GA-encapsulated CsA increased lymphatic drug delivery 4- to 18-fold over the ligand-free formulation and a commercial CsA capsule, respectively. Improved lymphatic bioavailability of CsA was paralleled by normalization of anti-double-stranded DNA immunoglobulin G titer, plasma cytokines, and glomerulonephritis. Thus, this study demonstrates the translational potential of nanoparticles that enhance the targeting of lymphatic tissues, transforming CsA into a potent single therapeutic for SLE.

Interferon regulatory factor 7 (IRF7) represents a link between inflammation and fibrosis in the pathogenesis of systemic sclerosis.

OBJECTIVES: There is considerable evidence that implicates dysregulation of type I interferon signalling (or type I IFN signature) in the pathogenesis of systemic sclerosis (SSc). Interferon regulatory factor 7 (IRF7) has been recognised as a master regulator of type I IFN signalling. The objective of this study was to elucidate the role of IRF7 in dermal fibrosis and SSc pathogenesis. METHODS: SSc and healthy control skin biopsies were investigated to determine IRF7 expression and activation. The role of IRF7 in fibrosis was investigated using IRF7 knockout (KO) mice in the bleomycin-induced and TSK/+mouse models. In vitro experiments with dermal fibroblasts from patients with SSc and healthy controls were performed. RESULTS: IRF7 expression was significantly upregulated and activated in SSc skin tissue and explanted SSc dermal fibroblasts compared with unaffected, matched controls. Moreover, IRF7 expression was stimulated by IFN-α in dermal fibroblasts. Importantly, IRF7 co-immunoprecipitated with Smad3, a key mediator of transforming growth factor (TGF)-ß signalling, and IRF7 knockdown reduced profibrotic factors in SSc fibroblasts. IRF7 KO mice demonstrated attenuated dermal fibrosis and inflammation compared with wild-type mice in response to bleomycin. Specifically, hydroxyproline content, dermal thickness as well as Col1a2, ACTA2 and interleukin-6 mRNA levels were significantly attenuated in IRF7 KO mice skin tissue. Furthermore, IRF7 KO in TSK/+mice attenuated hydroxyproline content, subcutaneous hypodermal thickness, Col1a2 mRNA as well as α-smooth muscle actin and fibronectin expression. CONCLUSIONS: IRF7 is upregulated in SSc skin, interacts with Smad3 and potentiates TGF-ß-mediated fibrosis, and therefore may represent a promising therapeutic target in SSc.

Macrophages and cadherins in fibrosis and systemic sclerosis.

PURPOSE OF REVIEW: Macrophages are key players in systemic sclerosis (SSc) and fibrosis. The mechanism by which macrophages regulate fibrogenesis is unclear and understanding the origin and function of macrophages is critical to developing effective therapeutics. Novel targets on macrophages are under investigation and recently, cadherins have emerged as a potential therapeutic target on macrophages. The current review will discuss the importance of macrophages in SSc and fibrosis and summarize recent studies on the role of cadherin-11 (Cdh11) on macrophages and fibrosis. RECENT FINDINGS: Genome-wide expression studies demonstrate the importance of macrophages in SSc and fibrosis. Although M2 macrophages are associated with fibrosis, the presence of a mixed M1/M2 phenotype in fibrosis has recently been reported. Several studies aiming to identify macrophage subsets involved in fibrogenesis suggest that monocyte-derived alveolar macrophages are key players in the development of murine lung fibrosis. Recent functional studies show that Cdh11 regulates macrophages, fibroblast invasion, and adhesion of macrophages to myofibroblasts. SUMMARY: Macrophages play an important role in SSc and fibrosis. New insights into the mechanisms by which macrophages regulate fibrogenesis have been discovered on the basis of Cdh11 studies and suggest that targeting Cdh11 may be an effective target to treat fibrosis.

Cadherin-11 contributes to liver fibrosis induced by carbon tetrachloride.

BACKGROUND AND AIMS: Liver fibrosis is characterized by the excessive deposition of extracellular matrix (ECM) leading to impaired function and cirrhosis. Previous reports support a role for cadherin-11 (CDH11) in regulating the development of dermal and pulmonary fibrosis. In the current report, the extent to which CDH11 modulates the development of liver fibrosis induced by carbon tetrachloride (CCL4) was assessed. METHODS: Wild type (WT) and CDH11 deficient (CDH11-/-) mice were treated with CCl4 or vehicle control for 8 weeks to induce liver fibrosis. Liver fibrosis was assessed by histology, collagen content, and RTPCR of fibrotic mediators. RESULTS: Livers from WT mice treated with CCl4 had increased levels of CDH11 which localized to injured hepatocytes, hepatic stellate cells, and macrophages. Interestingly, CDH11-/- mice had decreased histological evidence of liver fibrosis, collagen deposition, α-smooth muscle actin (α-SMA) accumulation, and mRNA levels of fibrotic mediators such as Col1-α1, Snail, TGF-ß and IL-6. CONCLUSIONS: These data demonstrate that CDH11 is increased during liver fibrosis, is an important regulator of liver fibrosis induced by CCL4 and suggest that CDH11 may be a potential therapeutic target for liver fibrosis.