Compromised phagosome maturation underlies RPE pathology in cell culture and whole animal models of Smith-Lemli-Opitz Syndrome.

Treatment of rats with the cholesterol pathway inhibitor AY9944 produces an animal model of Smith-Lemli-Opitz syndrome (SLOS), an autosomal recessive disease caused by defective cholesterol synthesis. This SLOS rat model undergoes progressive and irreversible degeneration of the neural retina, with associated pathological features of the retinal pigmented epithelium (RPE). Here, we provide further insights into the mechanism involved in the RPE pathology. In the SLOS rat model, markedly increased RPE apical autofluorescence is observed, compared to untreated animals, which correlates with increased levels of A2E and other bisretinoids. Utilizing cultured human induced pluripotent stem cell (iPSC)- derived SLOS RPE cells, we found significantly elevated steady-state levels of 7-dehydrocholesterol (7DHC) and decreased cholesterol levels (key biochemical hallmarks of SLOS). Western blot analysis revealed altered levels of the macroautophagy/autophagy markers MAP1LC3B-II and SQSTM1/p62, and build-up of ubiquitinated proteins. Accumulation of immature autophagosomes was accompanied by inefficient degradation of phagocytized, exogenously supplied retinal rod outer segments (as evidenced by persistence of the C-terminal 1D4 epitope of RHO [rhodopsin]) in SLOS RPE compared to iPSC-derived normal human control. SLOS RPE cells exhibited lysosomal pH levels and CTSD activity within normal physiological limits, thus discounting the involvement of perturbed lysosomal function. Furthermore, 1D4-positive phagosomes that accumulated in the RPE in both pharmacological and genetic rodent models of SLOS failed to fuse with lysosomes. Taken together, these observations suggest that defective phagosome maturation underlies the observed RPE pathology. The potential relevance of these findings to SLOS and the requirement of cholesterol for phagosome maturation are discussed.

Development of a Method to Determine the Level of Understanding of Package Inserts for Over-the-Counter Medication / 医薬品情報学

<b>Objective: </b>To develop a label comprehension study (LCS) of package inserts for over-the-counter medications in Japan, we evaluated whether it would be possible to detect differences in the level of understanding due to layout, and font size of different types of package insert using the interview method for LCS we developed previously.<br><b>Design: </b>A face-to-face questionnaire investigation.<br><b>Methods: </b>Two different types of package insert (including layout, and font size) for H₂-antagonists (package insert groups A and B) were used.  Study participants (≥18 years old) comprised consumers who visited a drugstore with a dispensing service in Saitama Prefecture.  They were randomly assigned to group A or B and divided by age range (young, 18-39 years; middle-aged, 40-59 years; eldely, ≥60 years).  First, the volunteers read the package insert with no time limitation and then answered 14 scenario-type questions during an interview to determine the level of understanding of the insert.  When both the correct answer and correct reason were given, the response was judged as correct.  The level of understanding of the package insert was calculated as the number of persons giving correct responses divided by all respondents.<br><b>Results: </b>Questionnaire responses from 86 consumers (43 in each group) were obtained.  The mean age in groups A and B was 46.5 years and 47.0 years, respectively.  The mean level of understanding of the package insert (14 questions) in groups A and B was 50.2 and 38.1%, respectively.  By age range, the mean level of understanding of the package insert in groups A and B in the young group was 60.6 and 56.9%, respectively, and there was no statistically significant difference between the two groups.  However, the mean level of understanding in groups A and B was 56.9 and 35.0% in the middle-aged group and 26.3 and 14.5% in the elderly group, respectively.  The mean understanding in group A was therefore higher than that in group B in both age ranges.  The association between understanding and age within groups indicated that with increasing age, understanding was lower in both groups (group A, <i>p</i>=0.001; group B, <i>p</i><0.001).  There was no difference in the level of understanding between the young and middle-aged in group A, but the difference in group B was greater than 20%.<br><b>Conclusion: </b>By comparing two package inserts of products in a similar pharmacological category using our LCS method, it suggested that font size and layout influenced consumers’ understanding of package inserts.  It might be able to evaluate the difference in the understanding of the package insert by using our LCS method.