Comparison of 5-year progression of retinitis pigmentosa involving the posterior pole among siblings by means of SD-OCT: a retrospective study

The blockchain technology promises to transform finance, money and evengovernments. However, analyses of blockchain applicability and robustness typicallyfocus on isolated systems whose actors contribute mainly by running the consensusalgorithm. Here, we highlight the importance of considering trustless platformswithin the broader ecosystem that includes social and communication networks. Asan example, we analyse the flash-crash observed on 21st June 2017 in the Ethereumplatform and show that a major phenomenon of social coordination led to acatastrophic cascade of events across several interconnected systems. We proposethe concept of “emergent centralisation” to describe situations where a single systembecomes critically important for the functioning of the whole ecosystem, and arguethat such situations are likely to become more and more frequent in interconnectedsocio-technical systems. We anticipate that the systemic approach we propose willhave implications for future assessments of trustless systems and call for the attentionof policy-makers on the fragility of our interconnected and rapidly changing world

Dominant Cone-Rod Dystrophy: A Mouse Model Generated by Gene Targeting of the GCAP1/Guca1a Gene

Cone dystrophy 3 (COD3) is a severe dominantly inherited retinal degeneration caused by missense mutations in GUCA1A, the gene encoding Guanylate Cyclase Activating Protein 1 (GCAP1). The role of GCAP1 in controlling cyclic nucleotide levels in photoreceptors has largely been elucidated using knock-out mice, but the disease pathology in these mice cannot be extrapolated directly to COD3 as this involves altered, rather than loss of, GCAP1 function. Therefore, in order to evaluate the pathology of this dominant disorder, we have introduced a point mutation into the murine Guca1a gene that causes an E155G amino acid substitution; this is one of the disease-causing mutations found in COD3 patients. Disease progression in this novel mouse model of cone dystrophy was determined by a variety of techniques including electroretinography (ERG), retinal histology, immunohistochemistry and measurement of cGMP levels. It was established that although retinal development was normal up to 3 months of age, there was a subsequent progressive decline in retinal function, with a far greater alteration in cone than rod responses, associated with a corresponding loss of photoreceptors. In addition, we have demonstrated that accumulation of cyclic GMP precedes the observed retinal degeneration and is likely to contribute to the disease mechanism. Importantly, this knock-in mutant mouse has many features in common with the human disease, thereby making it an excellent model to further probe disease pathogenesis and investigate therapeutic interventions

Identification and Functional Characterization of Complement Regulator-Acquiring Surface Protein 1 of the Lyme Disease Spirochetes Borrelia afzelii and Borrelia garinii

Complement regulator-acquiring surface protein 1 (CRASP-1) is the dominant factor-H-like protein 1 (FHL-1)- and factor-H-binding protein of Borrelia burgdorferi and is suggested to contribute to persistence of the pathogen. The prototype CRASP-1 of B. burgdorferi sensu stricto (CRASP-1Bb) has been formerly characterized. As shown recently, serum-resistant Borrelia afzelii strains express a unique FHL-1 and factor H-binding protein, designated CRASP-1Ba. Here, we describe for the first time the isolation and functional characterization of the gene encoding the full-length CRASP-1Ba of 28 kDa, which, upon processing, is predicted to be 26.4 kDa. CPASP-1Ba of B. afzelii spirochetes is associated with a genetic locus encoding the orthologous gbb54 gene family that maps to the linear plasmid of approximately 54 kb. Ligand affinity blotting techniques demonstrate that both native and recombinant CRASP-1Ba molecules strongly bind to FHL-1 and much more weakly to factor H. The FHL-1 and factor-H-binding site in CRASP-1Ba is shown to be localized to a 12-amino-acid residue domain at the C terminus of the protein. For comparison, the corresponding cspA-like gene(s) of a serum-sensitive Borrelia garinii strain has also been cloned and characterized. Most notably, two CRASP-1-related B. garinii proteins were identified; however, both molecules bind only weakly to FHL-1 and not at all to factor H. The present identification of the binding site of CRASP-1Ba represents an important step forward in our understanding of the pathogenesis of Lyme disease and may be helpful to design therapeutic regimens to interfere with complement evasion strategies of human pathogenic Borrelia strains

Mutational analyses of the BbCRASP-1 protein of Borrelia burgdorferi residues relevant for the architecture and binding of host complement regulators FHL-1 and factor H

Borrelia burgdorferi exploits multiple strategies to evade host immune responses. One central immune escape mechanism is the inactivation of the host complement attack by acquisition host complement regulators FHL-1 and factor H via complement regulator-acquiring surface proteins (BbCRASPs). The BbCRASP-1 protein is the first bacterial factor H/FHL-1-binding protein for which the atomic structure has been solved. Previously, 3 regions including the C terminus were identified as putative contact sites for the two complement regulators by the pepspot analysis. Based on the crystallographic structure an in vitro mutagenesis approach was conducted to identify amino acid residues which are relevant for FHL-1 and factor H binding by exchanging single or multiple residues in region 1 and the C-terminally located region 3. Single changes at 4 positions in region 1 either reduced (Lys136, Lys141, Glu147) or completely eliminated (Leu146) binding of both complement regulators. Substitutions clustered within the C-terminal region decreased (Glu234, Lys238, Tyr239, Lys241, Asp244, Thr245) or abolished binding (Lys240, Asp242, Leu246) of both complement regulators. Mapping the mutations onto the atomic structure of BbCRASP-1 reveals that, in contrast to earlier assumption, the C-terminal mutations act indirectly on FHL-1 and factor H binding, whilst the region 1 mutations map the site of direct complement regulator interaction. The elucidation of BbCRASP-1 structure - function may allow development of novel therapeutic strategies against Lyme disease

Mutational analyses of the BbCRASP-1 protein of Borrelia burgdorferi identify residues relevant for the architecture and binding of host complement regulators FHL-1 and factor H.

Borrelia burgdorferi exploits multiple strategies to evade host immune responses. One central immune escape mechanism is the inactivation of the host complement attack by acquisition host complement regulators FHL-1 and factor H via complement regulator-acquiring surface proteins (BbCRASPs). The BbCRASP-1 protein is the first bacterial factor H/FHL-1-binding protein for which the atomic structure has been solved. Previously, 3 regions including the C terminus were identified as putative contact sites for the two complement regulators by the pepspot analysis. Based on the crystallographic structure an in vitro mutagenesis approach was conducted to identify amino acid residues which are relevant for FHL-1 and factor H binding by exchanging single or multiple residues in region 1 and the C-terminally located region 3. Single changes at 4 positions in region 1 either reduced (Lys136, Lys141, Glu147) or completely eliminated (Leu146) binding of both complement regulators. Substitutions clustered within the C-terminal region decreased (Glu234, Lys238, Tyr239, Lys241, Asp244, Thr245) or abolished binding (Lys240, Asp242, Leu246) of both complement regulators. Mapping the mutations onto the atomic structure of BbCRASP-1 reveals that, in contrast to earlier assumption, the C-terminal mutations act indirectly on FHL-1 and factor H binding, whilst the region 1 mutations map the site of direct complement regulator interaction. The elucidation of BbCRASP-1 structure - function may allow development of novel therapeutic strategies against Lyme disease