ADAM9 inhibition increases membrane activity of ADAM10 and controls α-secretase processing of amyloid precursor protein.

Prodomains of A disintegrin and metalloproteinase (ADAM) metallopeptidases can act as highly specific intra- and intermolecular inhibitors of ADAM catalytic activity. The mouse ADAM9 prodomain (proA9; amino acids 24-204), expressed and characterized from Escherichia coli, is a competitive inhibitor of human ADAM9 catalytic/disintegrin domain with an overall inhibition constant of 280 ± 34 nM and high specificity toward ADAM9. In SY5Y neuroblastoma cells overexpressing amyloid precursor protein, proA9 treatment reduces the amount of endogenous ADAM10 enzyme in the medium while increasing membrane-bound ADAM10, as shown both by Western and activity assays with selective fluorescent peptide substrates using proteolytic activity matrix analysis. An increase in membrane-bound ADAM10 generates higher levels of soluble amyloid precursor protein α in the medium, whereas soluble amyloid precursor protein ß levels are decreased, demonstrating that inhibition of ADAM9 increases α-secretase activity on the cell membrane. Quantification of physiological ADAM10 substrates by a proteomic approach revealed that substrates, such as epidermal growth factor (EGF), HER2, osteoactivin, and CD40-ligand, are increased in the medium of BT474 breast tumor cells that were incubated with proA9, demonstrating that the regulation of ADAM10 by ADAM9 applies for many ADAM10 substrates. Taken together, our results demonstrate that ADAM10 activity is regulated by inhibition of ADAM9, and this regulation may be used to control shedding of amyloid precursor protein by enhancing α-secretase activity, a key regulatory step in the etiology of Alzheimer disease.

Perception of journal club seminars by medical doctoral students: results from five years of evaluation.

Objectives: A journal club is one of the well-established and popular methods of post-graduate education. In this work, we were interested to understand how the participants perceive journal club as a whole and how they evaluate their personal process of acquiring new scientific knowledge and development of soft-skills as an indispensable prerequisite of the lifelong learning. Project description: This study is a survey analysis examining perception of journal club sessions by post-graduate medical students. A checklist for journal club preparation as well as a questionnaire for evaluation of the journal club session by participants has been developed to determine if the journal club had met its aims. Data were collected by summing up all answers to each question of the questionnaire for each session. Qualitative data from a five-year evaluation period were compiled and analyzed. Results: The journal club checklist served as a guideline for the preparation of a journal club session as well as an evaluation questionnaire containing 24 items. Our work presents evidence that journal club seminars are well perceived by participants. Furthermore, a high percentage of participants deemed the working atmosphere to be constructive and found it worthwhile to participate in the sessions. The topics of the presentations have been positively evaluated, however only a minority of participants found that the topics of the journal club was related to their own specific research topic. Concerning the distribution of the journal article, we could show that distributing the paper one week before the journal club event provided sufficient time for preparation. Our evaluation revealed that two-thirds of the participants found discussions during journal club sessions rich and productive. The motivation to think more critically increased during journal club sessions. From our work, it is evident that the participants perceived the speakers´ soft-skills to have improved with the practice. Finally, we show a clear trend of improved perception of the value of journal club sessions from beginning to the end of the evaluation time. Conclusion: Based on the analyzed evaluations, we can conclude that journal club events are highly valued by participants and could be a good option for the development of certain soft-skills.

A Survey on the Integration of Spiritual Care in Medical Schools from the German-Speaking Faculties.

OBJECTIVE: Teaching about spirituality and health is recommended by the American Association of Medical Colleges and partially implemented in some US medical schools as well as in some faculties of other countries. We systematically surveyed Medical School Associate Deans for Student Affairs (ADSAs) in three German-speaking countries, assessing both projects on and attitudes towards Spiritual Care (SC) and the extent to which it is addressed in undergraduate (UME), graduate (GME), and continuing (CME) medical education (in this article, UME is understood as the complete basic medical education equivalent to college and Medical School. GME refers to the time of residency). METHODS: We executed a cross-sectional qualitative complete online-survey, addressing ADSAs of all accredited 46 medical schools in these countries. Anonymized responses could be analyzed from 25 (54.3%). RESULTS: No faculty provides a mandatory course exclusively dedicated to SC. Fourteen medical schools have UME courses or contents on SC, and 9 incorporate SC in mandatory classes addressing other topics. While most of the respondents indicate that spirituality is important for (a) the patients for coping and (b) for health care in general and thus, support the teaching of SC in UME, only half of them indicate a need for an SC curriculum in UME. Even if funding and training support were available, only a few of the respondents would agree to provide more of the sparse curricular time. CONCLUSION: A majority of the participating medical schools have curricular content on SC, predominantly in UME. However, most of the content is based on voluntary courses. Despite acknowledging its importance to patients, ADSAs and medical teachers are still reflecting on the divergences in patients' and doctors' spiritual orientations and its consequences for implementing spirituality into the medical education.

A new sandwich immunoassay for detection of the α-secretase cleaved, soluble amyloid-ß protein precursor in cerebrospinal fluid and serum.

Alzheimer's disease (AD) is the most common neurodegenerative disorder. Frequently used diagnostic biomarkers are amyloid-ß42 (Aß42), tau, and phospho-tau, which are measured in cerebrospinal fluid (CSF), and allow a reasonable, but not full, separation of AD patients and controls. Besides Aß42, additional proteolytic cleavage products of the amyloid-ß protein precursor (AßPP) have been investigated as potential biomarkers. This includes the α-secretase cleaved soluble AßPP ectodomain (sAßPPα). However, some studies found a reduction of sAßPPα, whereas other studies reported an increase of sAßPPα in the CSF of AD patients. The divergent findings may result from the detection of sAßPPα with antibodies, such as 6E10, which do not exclusively detect sAßPPα, but also the alternative ß-secretase cleavage product sAßPPß'. Here, we used the sAßPPα-specific antibody 14D6 and developed an ELISA-like sandwich immunoassay. The assay specifically detected sAßPPα in cell culture supernatants, in human CSF and even in serum, which is more readily accessible than CSF. The assay was used to analyze sAßPPα levels in CSF and serum of AD patients and controls. The assay detected a mild, but significant increase in sAßPPα in the CSF of AD patients compared to non-demented controls, while a mild reduction was observed in serum. The 14D6 assay in CSF allowed a better separation of AD patients from controls compared to the 6E10 antibody. Taken together, the new assay is widely applicable for specific sAßPPα measurement in culture media, CSF, and serum.