Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices.

Complement activation is key to anti-microbial defenses by directly acting on microbes and indirectly by triggering cellular immune responses. Complement activation may also contribute to the pathogenesis of numerous inflammatory and immunological diseases. Consequently, intense research focuses on developing therapeutics that block pathology-causing complement activation while preserving anti-microbial complement activities.

The PAR2 inhibitor I-287 selectively targets Gα and Gα signaling and has anti-inflammatory effects.

Protease-activated receptor-2 (PAR2) is involved in inflammatory responses and pain, therefore representing a promising therapeutic target for the treatment of immune-mediated inflammatory diseases. However, as for other GPCRs, PAR2 can activate multiple signaling pathways and those involved in inflammatory responses remain poorly defined. Here, we describe a new selective and potent PAR2 inhibitor (I-287) that shows functional selectivity by acting as a negative allosteric regulator on Gα and Gα activity and their downstream effectors, while having no effect on G signaling and βarrestin2 engagement.

Molecular and genetic inflammation networks in major human diseases.

It has been well-recognized that inflammation alongside tissue repair and damage maintaining tissue homeostasis determines the initiation and progression of complex diseases. Albeit with the accomplishment of having captured the most critical inflammation-involved molecules, genetic susceptibilities, epigenetic factors, and environmental factors, our schemata on the role of inflammation in complex diseases remain largely patchy, in part due to the success of reductionism in terms of research methodology per se. Omics data alongside the advances in data integration technologies have enabled reconstruction of molecular and genetic inflammation networks which shed light on the underlying pathophysiology of complex diseases or clinical conditions.

Assessing protein-RNA interactions using microfluidic capillary mobility shift assays.

We describe a novel method of characterizing protein-RNA interactions using a fluorescence-based multiwell capillary electrophoresis platform based on microfluidic technology. As a proof of concept, we studied the binding of human immunodeficiency virus 1 (HIV-1) transactivator of transcription (Tat) to the transactivation-responsive RNA (TAR). We established conditions to quantify the binding of recombinant HIV-1 Tat to TAR RNA and validated the assay by demonstrating the dependence of this interaction on the presence of the UCU bulge in TAR.

Identification of transforming growth factor beta1-driven genetic programs of acute lung fibrosis.

Lung fibrosis is characterized by excessive accumulation of extracellular matrix components leading to progressive airflow limitation. Distinct profibrotic pathways converge on the activation of transforming growth factor-beta (TGF-beta), a central growth factor implicated in most fibroproliferative diseases. Recently, enforced expression of bioactive human TGF-beta1 (hTGF-beta1) in lungs of transgenic mice was shown to recapitulate several key pathophysiologies observed in fibrotic disorders of the lung, including cellular inflammation, tissue fibrosis, and myofibroblast hyperplasia.

Visualization of looping involving the immunoglobulin heavy-chain locus in developing B cells.

The immunoglobulin heavy-chain (IgH) locus undergoes large-scale contraction in B cells poised to undergo IgH V(D)J recombination. We considered the possibility that looping of distinct IgH V regions plays a role in promoting long-range interactions. Here, we simultaneously visualize three subregions of the IgH locus, using three-dimensional fluorescence in situ hybridization.

E-proteins directly regulate expression of activation-induced deaminase in mature B cells.

Activated mature B cells in which the DNA-binding activity of E-proteins has been disrupted fail to undergo class switch recombination. Here we show that activated B cells overexpressing the antagonist helix-loop-helix protein Id3 do not induce expression of the murine Aicda gene encoding activation-induced deaminase (AID). A highly conserved intronic regulatory element in Aicda binds E-proteins both in vitro and in vivo.