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Background Systematic lupus erythematosus (SLE) is characterized with various complications which can cause serious organ damage in the human body. Despite the significant improvements in disease management of SLE patients, the non-invasive diagnosis is entirely missing. In this study, we used urinary peptidomic biomarkers for early diagnosis of disease onset to improve patient risk stratification, vital for effective drug treatment. Methods Urine samples from patients with SLE, lupus nephritis (LN) and healthy controls (HCs) were analyzed using capillary electrophoresis coupled to mass spectrometry (CE-MS) for state-of-the-art biomarker discovery. Results A biomarker panel made up of 65 urinary peptides was developed that accurately discriminated SLE without renal involvement from HC patients. The performance of the SLE-specific panel was validated in a multicentric independent cohort consisting of patients without SLE but with different renal disease and LN. This resulted in an area under the receiver operating characteristic (ROC) curve (AUC) of 0.80 (p < 0.0001, 95% confidence interval (CI) 0.65–0.90) corresponding to a sensitivity and a specificity of 83% and 73%, respectively. Based on the end terminal amino acid sequences of the biomarker peptides, an in silico methodology was used to identify the proteases that were up or down-regulated. This identified matrix metalloproteinases (MMPs) as being mainly responsible for the peptides fragmentation. Conclusions A laboratory-based urine test was successfully established for early diagnosis of SLE patients. Our approach determined the activity of several proteases and provided novel molecular information that could potentially influence treatment efficacy. [ABSTRACT FROM AUTHOR]

Allorejection and recurrence of autoimmunity are the major barriers to transplantation of islets of Langerhans for the cure of type 1 diabetes in humans. CD40-CD154 (CD40 ligand) interaction blockade by the use of anti-CD154 monoclonal antibody (mAb) has shown efficacy in preventing allorejection in several models of organ and cell transplantation. Here we report the beneficial effect of the chronic administration of a hamster anti-murine CD154 mAb, MR1, in prolonging islet graft survival in NOD mice. We explored the transplantation of C57BL/6 islets into spontaneously diabetic NOD mice, a combination in which both allogeneic and autoimmune components are implicated in graft loss. Recipients were treated either with an irrelevant control antibody or with MR1. MR1 administration was effective in prolonging allograft survival, but did not provide permanent protection from diabetes recurrence. The autoimmune component of graft loss was studied in spontaneously diabetic NOD mice that received syngeneic islets from young male NOD mice. In this combination, a less dramatic yet substantial delay in diabetes recurrence was observed in the MR1-treated recipients when compared with the control group. Finally, the allogeneic component was explored by transplanting C57BL/6 islets into chemically induced diabetic male NOD mice. In this setting, long-term graft survival (>100 days) was achieved in MR1-treated mice, whereas control recipients rejected their grafts within 25 days. In conclusion, chronic blockade of CD154 results in permanent protection from allorejection and significantly delays recurrence of diabetes in NOD mice. [ABSTRACT FROM AUTHOR]

Interleukin receptor-associated kinase 4 (IRAK4) is a key node of signaling within the innate immune system that regulates the production of inflammatory cytokines and chemokines. The presence of d amage- a ssociated m olecular patterns (DAMPs) after tissue damage such as stroke or traumatic brain injury (TBI) initiates signaling through the IRAK4 pathway that can lead to a feed-forward inflammatory loop that can ultimately hinder patient recovery. Herein, we describe the first potent, selective, and CNS-penetrant IRAK4 inhibitors for the treatment of neuroinflammation. Lead compounds from the series were evaluated in CNS PK/PD models of inflammation, as well as a mouse model of ischemic stroke. The SAR optimization detailed within culminates in the discovery of BIO-7488, a highly selective and potent IRAK4 inhibitor that is CNS penetrant and has excellent ADME properties.

TNF and IL-17 are two cytokines that drive dysregulated keratinocyte activity, and their targeting is highly efficacious in patients with psoriasis, but whether these molecules act with other inflammatory factors is not clear. Here, we show that mice having a keratinocyte-specific deletion of Fn14 ( Tnfrsf12a ), the receptor for the TNF superfamily cytokine TWEAK ( Tnfsf12 ), displayed reduced imiquimod-induced skin inflammation, including diminished epidermal hyperplasia and less expression of psoriasis signature genes. This corresponded with Fn14 being expressed in keratinocytes in human psoriasis lesions and TWEAK being found in several subsets of skin cells. Transcriptomic studies in human keratinocytes revealed that TWEAK strongly overlaps with IL-17A and TNF in up-regulating the expression of CXC chemokines, along with cytokines such as IL-23 and inflammation-associated proteins like S100A8/9 and SERPINB1/B9, all previously found to be highly expressed in the lesional skin of patients with psoriasis. TWEAK displayed strong synergism with TNF or IL-17A in up-regulating messenger RNA for many psoriasis-associated genes in human keratinocytes, including IL23A , IL36G , and multiple chemokines, implying that TWEAK acts with TNF and IL-17 to enhance feedback inflammatory activity. Correspondingly, therapeutic treatment of mice with anti-TWEAK was equally as effective as antibodies to IL-17A or TNF in reducing clinical and immunological features of psoriasis-like skin inflammation and combination targeting of TWEAK with either cytokine had no greater inhibitory effect, reinforcing the conclusion that all three cytokines function together. Thus, blocking TWEAK could be comparable to targeting TNF or IL-17 and might be considered as an alternate therapeutic treatment for psoriasis.

CX3CR1, one of the highest expressed genes in microglia in mice and humans, is implicated in numerous microglial functions. However, the molecular mechanisms underlying Cx3cr1 signaling are not well understood. Here, we analyzed transcriptomes of Cx3cr1- deficient microglia under varying conditions by RNA-sequencing (RNA-seq). In 2-mo-old mice, Cx3cr1 deletion resulted in the down-regulation of a subset of immune-related genes, without substantial epigenetic changes in markers of active chromatin. Surprisingly, Cx3cr1- deficient microglia from young mice exhibited a transcriptome consistent with that of aged Cx3cr1- sufficient animals, suggesting a premature aging transcriptomic signature. Immunohistochemical analysis of microglia in young and aged mice revealed that loss of Cx3cr1 modulates microglial morphology in a comparable fashion. Our results suggest that CX3CR1 may regulate microglial function in part by modulating the expression levels of a subset of inflammatory genes during chronological aging, making Cx3cr1 -deficient mice useful for studying aged microglia., (© 2019 Gyoneva et al.)