We also noted functional distinctions between sinus and tracheal glands in the trachea

We have previously described the neuroprotection afforded by Y-27632 in Drosophila and in R6/2 mice with systemic administration. HA-1077 is a ROCK inhibitor approved for clinical use in Japan. It is employed to suppress vasospasm in subarachnoid hemorrhage. We have previously observed that HA-1077 is more effective than Y- 27632 in suppressing phosphorylation of profilin at Ser-137. It has a chemical structure distinct from Y-27632, and thus also serves as an additional validation of the putative target, ROCK. Preliminary experiments revealed that the half-life of HA-1077 injected directly into the eye was less than 24 hrs, indicating that a more sustained release would be necessary. To improve the bioavailability of HA-1077, we packaged it into liposomes using palmitoyloleoylphosphatidylcholine and cholesterol with remote loading approaches. This method of drug delivery has been shown to provide sustained release within the intra-ocular space over several weeks. This study used ERG as a rapid, non-invasive measure of neuronal function in the R6/2 mouse model of HD to test a candidate therapeutic pathway. To begin, we established the characteristics of the progressive retinal pathology in R6/2 mice. We observed reduced photopic ERG responses at all ages examined, and a steady decline between 6 and 11 weeks of age. This was accompanied by loss of cone photoreceptors beginning at 10 weeks of age, at which time a progressive disorganization began in the outer retina. This roughly parallels decreases in rotarod performance in this line that we have previously observed in our laboratory. By packaging HA-1077 within liposomes, we were able to deliver the compound on a sustained basis following a single intravitreal injection. We treated two cohorts of animals with different doses of HA-1077, using injection of the contralateral eye with empty liposomes as an internal control. This, coupled with the rapid ERG changes, allowed us to reduce the time and number of animals required to carry out the trial versus a conventional approach. HA-1077 treatment reduced the amount of phospho-profilin in the retina, indicating that we were hitting our therapeutic target. Chronic treatment with a single injection of HA-1077 improved photopic ERG response amplitudes by 40-60%. These data indicate that ROCK inhibition reduces expanded Htt toxicity, possibly by inhibiting profilin phosphorylation. Testing of lead compounds in mice is expensive, time consuming and labor-intensive. Further, systemic administration of a compound must achieve adequate CNS levels, and inevitably leaves doubts about whether CNS neurons vs. peripheral tissues might be responsible for any improved behavior outcome. By contrast, it has been suggested that the retinal dystrophy in mutant mice might serve as a facile model for therapy in polyglutamine diseases. Here we have demonstrated the feasibility of using retinal physiology as a robust readout of a therapeutic effect in vivo. The retina is one part of the CNS that is readily accessible to chemical and genetic treatment. It is also uniquely amenable to accurately monitor neuronal physiology non-invasively via ERG. Although not used here, fundoscopy and optical coherence tomography can also be employed to image neural anatomy in situ. Because any therapeutic trial can be conducted using the contralateral eye as an internal control, the number of animals needed to observe a statistically significant effect is vastly reduced. In this case, we have used the R6/2 mouse, which overexpresses an N-terminal exon 1 fragment of the Htt protein. Our studies here suggest that it should be possible to model toxicity in vivo for a variety of pathogenic proteins, simply by engineering animals that feature retina-specific expression. The use of the retina also allows modifications to be carried out on a very defined group of neurons, thus ensuring that specific CNS responses are linked directly to the targeted cells. Future work will help determine the predictive value of this system with other compounds that have demonstrated efficacy in standard transgenic models, and may ultimately speed preclinical testing. Oral biofilms play an important role in periodontal disease, a primary reason for human adult tooth loss. With more than 700 species identified in the oral cavity, this biofilm presents a complex and dynamic ecosystem, whose growth is dictated by microenvironmental factors. As proof of concept, studies in murine models have demonstrated the multiple species biofilms display increased pathogenicity, reflecting the increased alveolar bone loss, which is the hallmark of periodontitis.