Description: As a strategy to treat Duchenne muscular dystrophy, we used arginine butyrate, which combines two pharmacological activities: nitric oxide pathway activation, and histone deacetylase inhibition. Continuous intraperitoneal administration to dystrophin-deficient mdx mice resulted in a near 2-fold increase in utrophin (protein homologous to dystrophin) in skeletal muscle, heart, and brain, accompanied by an improvement of the dystrophic phenotype in both adult and newborn mice (45 and 70% decrease in creatine kinase level, respectively; 14% increase in tidal volume, 30% decrease in necrotic area in limb and 23% increase in isometric force). Intermittent administration, as performed in clinical trials, was then used to reduce the frequency of injections and to improve safety. This also enhanced utrophin level around 2-fold (EC 50 =284 mg/ml) and alleviated the dystrophic phenotype (inverted grid and grip test performance near to wild-type values, creatine kinase level decreased by 50%). Skin biopsies were used to monitor treatment efficacy, instead of invasive muscle biopsies, and this could be done a few days after the start of treatment. A 2-fold increase in utrophin expression was also shown in cultured human myotubes. In vivo and in vitro experiments demonstrated that the drug combination acts synergistically. Together, these data constitute a proof of principle of the beneficial effects of arginine butyrate on muscular dystrophy.—Vianello, S., Yu, H., Voisin, V., Haddad, H., He, X., Foutz, A. S., Sebrié, C., Gillet, B., Roulot, M., Fougerousse, F., Perronnet, C., Vaillend, C., Matecki, S., Escolar, D., Bossi, L., Israël, M., de la Porte, S. Arginine butyrate: a therapeutic candidate for Duchenne muscular dystrophy.

Description: Caspases are important regulators and executioners in the apoptosis pathways and play crucial roles in carcinogenesis. We tested the hypothesis that functional variants of CASP genes are associated with risk of squamous cell carcinoma of the head and neck (SCCHN) and second primary malignancy (SPM). We genotyped 7 selected, potentially functional single nucleotide polymorphisms (SNPs) located in the microRNA binding sites of the 3' untranslational region (UTR; 2 in CASP3 , 1 in CASP6 , and 4 in CASP7 ) and evaluated their associations first with risk of SCCHN in 1066 patients with SCCHN and 1074 cancer-free control subjects and then with SPM in 846 patients in the same non-Hispanic white study population. We found that compared with the CASP3 TT genotype of rs1049253, the variant TC/CC genotypes were associated with significantly increased risk of SCCHN (adjusted odds ratio=1.29 and 95% confidence interval=1.07-1.56) and SPM (adjusted hazard ratio=1.79 and 95% CI=1.02–3.16) and worse SPM-free survival (log-rank P = 0.020), but no associations were found for the other 6 SNPs. We then performed additional experiments to seek functional relevance of the rs1049253 SNP. First, the luciferase activity and miR-885-5p mimic transfection tests suggested that CASP3 was the target of miR-885-5p and that rs1049253T〉C resulted in altered regulation of the CASP3 expression. Second, the rs1049253 CC genotype was associated with reduced levels of CASP3 mRNA in peripheral blood mononuclear cells from 118 SCCHN patients and 103 cancer-free control subjects and lower levels of CASP3 protein expression in 11 head and neck cancer cell lines, compared with the TT genotype. Taken together, our data suggest that the miR-885-5p binding site rs1049253T〉C SNP in the 3'-UTR of CASP3 modulates CASP3 expression at both mRNA and protein levels and thus contributes to SCCHN susceptibility. Guan, X., Liu, Z., Liu, H., Yu, H., Wang, L.-E., Sturgis, E. M., Li, G., and Wei, Q. A functional variant at the miR-885-5p binding site of CASP3 confers risk of both index and second primary malignancies in patients with head and neck cancer.

Description: The CD40/CD40L dyad is deemed to play a central role in several inflammatory processes, including atherosclerosis. As CD40 is overexpressed in atherosclerotic lesions, it constitutes a promising candidate for targeted imaging approaches. Here we describe the design of a novel, selective peptide ligand for CD40 by phage display. A synthetic peptide corresponding with the phage insert NP31 displayed nanomolar affinity for CD40. Affinity was further enhanced by mutimeric presentation of NP31. An essential 11-mer peptide motif was identified by truncation and alanine scan studies. Enriched phage selectively bound human CD40 and homed to inflammatory joints in a murine model of rheumatoid arthritis. NP31 ablated VEGF and IL-6 transcriptional activation and partially inhibited IL-6 production by CD40L-activated endothelial cells. Notably, NP31 did not only alter the biodistribution profile of a streptavidin scaffold but also markedly increased accumulation of the carrier in atherosclerotic aortic lesions of aged ApoE –/– mice in a CD40-dependent manner. This potent and selective peptide ligand has potential for targeted imaging and drug delivery approaches in CD40-dependent inflammatory disorders such as atherosclerosis.—Yu, H., Segers, F., Sliedregt-Bol, K., Bot, I., Woltman, A. M. , Boross, P., Verbeek, S., Overkleeft, H., van der Marel, G. A., van Kooten, C., van Berkel, T. J. C., Biessen, E. A. L. Identification of a novel CD40 ligand for targeted imaging of inflammatory plaques by phage display.

Description: Siglecs are sialic acid-binding Ig-like lectins that recognize sialoglycans via amino-terminal V-set domains. CD33-related Siglecs (CD33rSiglecs) on innate immune cells recognize endogenous sialoglycans as "self-associated molecular patterns" (SAMPs), dampening immune responses via cytosolic immunoreceptor tyrosine-based inhibition motifs that recruit tyrosine phosphatases. However, sialic acid-expressing pathogens subvert this mechanism through molecular mimicry. Meanwhile, endogenous host SAMPs must continually evolve to evade other pathogens that exploit sialic acids as invasion targets. We hypothesized that these opposing selection forces have accelerated CD33rSiglec evolution. We address this by comparative analysis of major CD33rSiglec (Siglec-3, Siglec-5, and Siglec-9) orthologs in humans, chimpanzees, and baboons. Recombinant soluble molecules displaying ligand-binding domains show marked quantitative and qualitative interspecies differences in interactions with strains of the sialylated pathogen, group B Streptococcus , and with sialoglycans presented as gangliosides or in the form of sialoglycan microarrays, including variations such as N -glycolyl and O -acetyl groups. Primate Siglecs also show quantitative and qualitative intra- and interspecies variations in expression patterns on leukocytes, both in circulation and in tissues. Taken together our data explain why the CD33rSiglec-encoding gene cluster is undergoing rapid evolution via multiple mechanisms, driven by the need to maintain self-recognition by innate immune cells, while escaping 2 distinct mechanisms of pathogen subversion.—Padler-Karavani, V., Hurtado-Ziola, N., Chang, Y.-C., Sonnenburg, J. L., Ronaghy, A., Yu, H., Verhagen, A., Nizet, V., Chen, X., Varki, N., Varki, A., Angata, T. Rapid evolution of binding specificities and expression patterns of inhibitory CD33-related Siglecs in primates.