Severe and acute complications of biologics in psoriasis.

Biologic therapies have revolutionized the approach to immune-mediated diseases such as psoriasis. Due to their favorable safety profiles and excellent efficacy, biologic agents are considered the gold standard for moderate-to-severe psoriasis. The aim of this paper is to saliently review the severe and acute complications of the Food and Drug Administration (FDA) approved biologic agents for psoriasis. Reviewed agents include tumor necrosis factor alpha inhibitors (etanercept, infliximab, and adalimumab), interleukin 12/23 inhibitors (ustekinumab), and interleukin 17 (IL-17) inhibitors (secukinumab and ixekizumab). While malignancies, serious infections, and major adverse cardiovascular events have been reported, their association with biologic therapy are not hypothesized as causal. However, IL-17 inhibitors appear to cause exacerbations and new cases of inflammatory bowel disease. While more long-term studies are warranted in understanding the biologic's long-term side effect profile, short-term studies have confirmed that the biologics are some of the safest treatment options for psoriasis. Nevertheless, certain populations yield higher risk to acute complications with the biologics than others - physicians must use their judgement and vigilance when monitoring and treating patients undergoing therapy with biological agents.

The genes that encode the gonococcal transferrin binding proteins, TbpB and TbpA, are differentially regulated by MisR under iron-replete and iron-depleted conditions.

Neisseria gonorrhoeae produces two transferrin binding proteins, TbpA and TbpB, which together enable efficient iron transport from human transferrin. We demonstrate that expression of the tbp genes is controlled by MisR, a response regulator in the two-component regulatory system that also includes the sensor kinase MisS. The tbp genes were up-regulated in the misR mutant under iron-replete conditions but were conversely down-regulated in the misR mutant under iron-depleted conditions. The misR mutant was capable of transferrin-iron uptake at only 50% of wild-type levels, consistent with decreased tbp expression. We demonstrate that phosphorylated MisR specifically binds to the tbpBA promoter and that MisR interacts with five regions upstream of the tbpB start codon. These analyses confirm that MisR directly regulates tbpBA expression. The MisR binding sites in the gonococcus are only partially conserved in Neisseria meningitidis, which may explain why tbpBA was not MisR-regulated in previous studies using this related pathogen. This is the first report of a trans-acting protein factor other than Fur that can directly contribute to gonococcal tbpBA regulation.

Beyond the Crystal Structure: Insight into the Function and Vaccine Potential of TbpA Expressed by Neisseria gonorrhoeae.

Neisseria gonorrhoeae, the causative agent of the sexually transmitted infection gonorrhea, is not preventable by vaccination and is rapidly developing resistance to antibiotics. However, the transferrin (Tf) receptor system, composed of TbpA and TbpB, is an ideal target for novel therapeutics and vaccine development. Using a three-dimensional structure of gonococcal TbpA, we investigated two hypotheses, i.e., that loop-derived antibodies can interrupt ligand-receptor interactions in the native bacterium and that the loop 3 helix is a critical functional domain. Preliminary loop-derived antibodies, as well as optimized second-generation antibodies, demonstrated similar modest ligand-blocking effects on the gonococcal surface but different effects in Escherichia coli. Mutagenesis of loop 3 helix residues was employed, generating 11 mutants. We separately analyzed the mutants' abilities to (i) bind Tf and (ii) internalize Tf-bound iron in the absence of the coreceptor TbpB. Single residue mutations resulted in up to 60% reductions in ligand binding and up to 85% reductions in iron utilization. All strains were capable of growing on Tf as the sole iron source. Interestingly, in the presence of TbpB, only a 30% reduction in Tf-iron utilization was observed, indicating that the coreceptor can compensate for TbpA impairment. Complete deletion of the loop 3 helix of TbpA eliminated the abilities to bind Tf, internalize iron, and grow with Tf as the sole iron source. Our studies demonstrate that while the loop 3 helix is a key functional domain, its function does not exclusively rely on any single residue.

GRP78/BiP/HSPA5/Dna K is a universal therapeutic target for human disease.

The chaperone GRP78/Dna K is conserved throughout evolution down to prokaryotes. The GRP78 inhibitor OSU-03012 (AR-12) interacted with sildenafil (Viagra) or tadalafil (Cialis) to rapidly reduce GRP78 levels in eukaryotes and as a single agent reduce Dna K levels in prokaryotes. Similar data with the drug combination were obtained for: HSP70, HSP90, GRP94, GRP58, HSP27, HSP40 and HSP60. OSU-03012/sildenafil treatment killed brain cancer stem cells and decreased the expression of: NPC1 and TIM1; LAMP1; and NTCP1, receptors for Ebola/Marburg/Hepatitis A, Lassa fever, and Hepatitis B viruses, respectively. Pre-treatment with OSU-03012/sildenafil reduced expression of the coxsakie and adenovirus receptor in parallel with it also reducing the ability of a serotype 5 adenovirus or coxsakie virus B4 to infect and to reproduce. Similar data were obtained using Chikungunya, Mumps, Measles, Rubella, RSV, CMV, and Influenza viruses. OSU-03012 as a single agent at clinically relevant concentrations killed laboratory generated antibiotic resistant E. coli and clinical isolate multi-drug resistant N. gonorrhoeae and MRSE which was in bacteria associated with reduced Dna K and Rec A expression. The PDE5 inhibitors sildenafil or tadalafil enhanced OSU-03012 killing in N. gonorrhoeae and MRSE and low marginally toxic doses of OSU-03012 could restore bacterial sensitivity in N. gonorrhoeae to multiple antibiotics. Thus, Dna K and bacterial phosphodiesterases are novel antibiotic targets, and inhibition of GRP78 is of therapeutic utility for cancer and also for bacterial and viral infections.

A simple method for the evaluation of microfluidic architecture using flow quantitation via a multiplexed fluidic resistance measurement.

Quality control of microdevices adds significant costs, in time and money, to any fabrication process. A simple, rapid quantitative method for the post-fabrication characterization of microchannel architecture using the measurement of flow with volumes relevant to microfluidics is presented. By measuring the mass of a dye solution passed through the device, it circumvents traditional gravimetric and interface-tracking methods that suffer from variable evaporation rates and the increased error associated with smaller volumes. The multiplexed fluidic resistance (MFR) measurement method measures flow via stable visible-wavelength dyes, a standard spectrophotometer and common laboratory glassware. Individual dyes are used as molecular markers of flow for individual channels, and in channel architectures where multiple channels terminate at a common reservoir, spectral deconvolution reveals the individual flow contributions. On-chip, this method was found to maintain accurate flow measurement at lower flow rates than the gravimetric approach. Multiple dyes are shown to allow for independent measurement of multiple flows on the same device simultaneously. We demonstrate that this technique is applicable for measuring the fluidic resistance, which is dependent on channel dimensions, in four fluidically connected channels simultaneously, ultimately determining that one chip was partially collapsed and, therefore, unusable for its intended purpose. This method is thus shown to be widely useful in troubleshooting microfluidic flow characteristics.

Photostimulation of Phox2b medullary neurons activates cardiorespiratory function in conscious rats.

RATIONALE: Hypoventilation is typically treated with positive pressure ventilation or, in extreme cases, by phrenic nerve stimulation. This preclinical study explores whether direct stimulation of central chemoreceptors could be used as an alternative method to stimulate breathing. OBJECTIVES: To determine whether activation of the retrotrapezoid nucleus (RTN), which is located in the rostral ventrolateral medulla (RVLM), stimulates breathing with appropriate selectivity. METHODS: A lentivirus was used to induce expression of the photoactivatable cationic channel channelrhodopsin-2 (ChR2) by RVLM Phox2b-containing neurons, a population that consists of central chemoreceptors (the ccRTN neurons) and blood pressure (BP)-regulating neurons (the C1 cells). The transfected neurons were activated with pulses of laser light. Respiratory effects were measured by plethysmography or diaphragmatic EMG recording and cardiovascular effects by monitoring BP, renal sympathetic nerve discharge, and the baroreflex. MEASUREMENTS AND MAIN RESULTS: The RVLM contained 600 to 900 ChR2-transfected neurons (63% C1, 37% ccRTN). RVLM photostimulation significantly increased breathing rate (+42%), tidal volume (21%), minute volume (68%), and peak expiratory flow (48%). Photostimulation increased diaphragm EMG amplitude (19%) and frequency (21%). Photostimulation increased BP (4 mmHg) and renal sympathetic nerve discharge (43%) while decreasing heart rate (15 bpm). CONCLUSIONS: Photostimulation of ChR2-transfected RVLM Phox2b neurons produces a vigorous stimulation of breathing accompanied by a small sympathetically mediated increase in BP. These results demonstrate that breathing can be relatively selectively activated in resting unanesthetized mammals via optogenetic manipulation of RVLM neurons presumed to be central chemoreceptors. This methodology could perhaps be used in the future to enhance respiration in humans.