Failure of remyelination is largely responsible for sustained neurologic symptoms in multiple sclerosis (MS). MS lesions contain hyaluronan deposits that inhibit oligodendrocyte precursor cell (OPC) maturation. However, the mechanism behind this inhibition is unclear. We report here that Toll-like receptor 2 (TLR2) is expressed by oligodendrocytes and is up-regulated in MS lesions. Pathogenderived TLR2 agonists, but not agonists for other TLRs, inhibit OPC maturation in vitro. Hyaluronan-mediated inhibition of OPC maturation requires TLR2 and MyD88, a TLR2 adaptor molecule. Ablated expression of TLR2 also enhances remyelination in a lysolecithin animal model. Hyaluronidases expressed by OPCs degrade hyaluronan to hyaluronan oligomers, a requirement for hyaluronan/TLR2 signaling. MS lesions contain both TLR2 + oligodendrocytes and lowmolecular-weight hyaluronan, consistent with their importance to remyelination in MS. We thus have defined a mechanism controlling remyelination failure in MS where hyaluronan is degraded by hyaluronidases into hyaluronan oligomers that block OPC maturation and remyelination through TLR2-MyD88 signaling.hyaluronidase | MyD88 | innate immunity I n multiple sclerosis (MS), destruction of CNS myelin accounts for a majority of neurologic symptoms. MS patients typically exhibit a relapsing/remitting course in which relapses result from inflammation and demyelination and remissions result from resolution of inflammation and remyelination. Secondary progressive MS, which typically begins in patients after a decade of relapsing/ remitting MS, exhibits irreversible neurologic disability.Most chronic MS lesions show little if any remyelination. The failure of remyelination in MS theoretically could be the consequence of a deficiency in the number of oligodendrocyte progenitor cells (OPCs), absence of a promyelination signal, or the presence of inhibitory influences on OPCs. It therefore is of interest that the histopathology of the MS lesion has revealed the presence of OPCs and premyelinating oligodendrocytes in chronic MS lesions. The premyelinating oligodendrocytes extend processes that contact but fail to myelinate axons (1-4), thus suggesting failure of remyelination is caused by the loss of promyelination signals or the presence of inhibitory signals.Recently, the glycosaminoglycan hyaluronan was identified within MS lesions and found to inhibit OPC maturation and remyelination in an MS animal model (5). The mechanism underlying this inhibition is unknown. Because hyaluronan can function as an endogenous mammalian ligand for Toll-like receptors (TLRs) 2 and 4 in innate immune cell activation (6-9), we reasoned that TLR stimulation also may be required for hyaluronan-mediated blocking of OPC maturation.Although TLRs and the Drosophila ortholog Toll have welldescribed functions in innate immune cells (6-12), TLRs also have potent functions outside the immune system. Toll and TLR have diverse roles in axonal pathfinding, dorsoventral patterning, and cell-fate determination (13). In particul...

BACKGROUND: Tocilizumab, an IL-6 receptor antagonist, can be used to treat cytokine release syndrome (CRS), with observed improvements in a coronavirus disease 2019 (COVID-19) case series. RESEARCH QUESTION: The goal of this study was to determine if tocilizumab benefits patients hospitalized with COVID-19.

Cohesive scientific evidence from molecular, animal, and human investigations supports the hypothesis that constitutive overexpression of cyclooxygenase-2 (COX-2) is a ubiquitous driver of mammary carcinogenesis, and reciprocally, that COX-2 blockade has strong potential for breast cancer prevention and therapy. Key findings include the following: (1) COX-2 is constitutively expressed throughout breast cancer development and expression intensifies with stage at detection, cancer progression and metastasis; (2) essential features of mammary carcinogenesis (mutagenesis, mitogenesis, angiogenesis, reduced apoptosis, metastasis and immunosuppression) are linked to COX-2-driven prostaglandin E2 (PGE-2) biosynthesis; (3) upregulation of COX-2 and PGE-2 expression induces transcription of CYP-19 and aromatase-catalyzed estrogen biosynthesis which stimulates unbridled mitogenesis; (4) extrahepatic CYP-1B1 in mammary adipose tissue converts paracrine estrogen to carcinogenic quinones with mutagenic impact; and (5) agents that inhibit COX-2 reduce the risk of breast cancer in women without disease and reduce recurrence risk and mortality in women with breast cancer. Recent sharp increases in global breast cancer incidence and mortality are likely driven by chronic inflammation of mammary adipose and upregulation of COX-2 associated with the obesity pandemic. The totality of evidence clearly supports the supposition that mammary carcinogenesis often evolves as a progressive series of highly specific cellular and molecular changes in response to induction of constitutive overexpression of COX-2 and the prostaglandin cascade in the "inflammogenesis of breast cancer". Key words: Breast Cancer; Cyclooxygenase-2; Nonsteroidal anti-inflammatory drugs; Inflammogenesis; Estrogen; Aromatase Core tip: Mammary carcinogenesis often evolves as a series of highly specific cellular and molecular changes in response to induction of constitutive over-expression of cyclooxygenase-2 (COX-2) and the prostaglandin cascade; reciprocally, agents that block COX-2 have significant value in the chemoprevention and therapy of breast cancer.Harris RE, Casto BC, Harris ZM. Cyclooxygenase-2 and the inflammogenesis of breast cancer. World J Clin Oncol 2014; 5(4): 677-692 Available from: URL: http://www.wjgnet.com/2218-4333/full/v5/ i4/677.htm DOI: http://dx.doi.org/10.5306/wjco.v5.i4.677 INTRODUCTIONMore than a century ago, Virchow et al [1,2] chronic inflammation leads to cancer development by increasing cellular proliferation [3] . Various models of carcinogenesis have been proposed involving inflammatory stimuli and mediators of wound healing [4][5][6] . The recent discovery of the inducible cyclooxygenase-2 (COX-2) gene has rekindled interest in the causal link between inflammation and cancer, and various models of carcinogenesis have been proposed involving inflammatory stimuli and COX-2 expression [7][8][9][10] . The current review synthesizes and interprets the accumulating body of evidence supporting COX-2 driven inflammogenesis as a ge...

Bacteriophage therapy, which uses lytic viruses as antimicrobials, has received renewed interest to address the emerging antimicrobial resistance (AMR) crisis. Cystic fibrosis (CF), a disease complicated by recurrent P. aeruginosa pulmonary infections that cause lung function decline, is an example where AMR is already a clinical problem. While bacteria evolve bacteriophage resistance, we developed a strategy to select bacteriophages that target bacterial cell surface receptors that contribute to antibiotic resistance or virulence. Thus, in addition to killing bacteria, these phages steer surviving, evolved bacteria to antibiotic re-sensitivity or attenuated virulence. Here, we present outcomes from nine CF adults treated with nebulized bacteriophage therapy for AMR P. aeruginosa using this personalized approach. Results showed that phage therapy: 1) reduced sputum P. aeruginosa, 2) showed evidence for predicted trade-offs in most subjects, and 3) improved lung function, which may reflect the combined effects of decreased bacterial sputum density and phage-driven evolved trade-offs.

There is a lot of interest in exactly how nucleic acid duplexes are affected by the addition of certain stabilizing and destabilizing metabolites. Unfortunately, the differences in reaction conditions between published reports often precludes a comparison of the results, effectively preventing a cohesive strategy for predicting additive effects on nucleic acid stability. This information is critically important for obtaining a fundamental understanding of how additives, including metabolites, alter DNA and RNA stability and structure. We now show that the destabilization of nucleic acids by the metabolite trehalose in standard optical melting buffer (20 mM sodium cacodylate, 1M NaCl, and 0.5 mM EDTA) differs from that of a common PCR buffer, and a simulated physiological buffer, with up to an 8°C melting temperature difference. We also demonstrate that the extent of DNA destabilization due to trehalose depends on DNA length and depends on percent GC content, at least for the primer-length duplexes studied here. Furthermore, we show that glucose (a monomer) is not quite as effective a destabilizer as trehalose (a dimer). The implications of these results related to trehalose-destabilization of DNA, related to conducting and analyzing DNA-additive experiments, and related to using this type of data for predictive purposes are discussed.