An effective non-hormonal option with high tolerability for mild to moderate symptoms of vaginal dryness associated with menopause.

OBJECTIVES: The efficacy and tolerability of a non-hormonal pessary (that forms an oil-in-water emollient with the vaginal fluid) were assessed for the treatment of symptoms of vaginal dryness associated with menopause. STUDY DESIGN: Seventy-nine postmenopausal women (mean age 60.8 ± 6.5 years) with mild to moderate symptoms of vaginal dryness (including dyspareunia) were enrolled in this open-label, prospective, post-market clinical follow-up trial, conducted in 2022 by one research center in Germany. The investigational pessary was applied for the first 7 days once daily and the subsequent 31 days twice a week, at bedtime. A treatment-free period of 6 days completed the trial. MAIN OUTCOME MEASURES: During the trial, participants filled out questionnaires that enabled the calculation of a total severity score for subjective symptoms of atrophy-related vaginal dryness and impairment of daily as well as sexual life. Furthermore, vaginal health index and safety were studied. RESULTS: A rapid and significant reduction in the severity scores for symptoms was observed over the 38-day course of treatment and beyond. Quality of life assessed by DIVA (day-to-day impact of vaginal aging) questionnaire, dyspareunia and vaginal health index also clearly improved. The tolerability was mainly rated as "good to very good" by the investigator and 94.9 % of participants. The vast majority were very satisfied with the simple and pleasant handling. No serious adverse events occurred. CONCLUSION: Overall, the presented data suggest that the investigated non-hormonal pessary is an effective and well tolerated treatment option for vaginal symptoms associated with dryness, thus improving quality of life for women, even those who are sexually active. CLINICALTRIALS: gov identifier NCT05211505.

A novel role for the non-catalytic intracellular domain of Neprilysins in muscle physiology.

BACKGROUND INFORMATION: Neprilysins (Neps) are membrane-bound M13 endopeptidases responsible for the activation and/or inactivation of peptide signalling events on cell surfaces. By hydrolysing their respective substrates, mammalian Neps are crucial to the metabolism of numerous bioactive peptides, especially in the nervous, immune, cardiovascular and inflammatory systems. On the basis of their involvement in essential physiological processes, proteins of the Nep family constitute putative therapeutic agents as well as targets in different diseases, including Alzheimer's disease. RESULTS: We here demonstrate that overexpression of Neprilysin 4 (Nep4) in Drosophila melanogaster leads to a severe muscle degeneration phenotype. This phenotype is observed for overexpression of full-length Nep4 in somatic muscles and is accompanied by severely impaired movement of larvae and lethality in late larval development. On the contrary, down-regulation of expression caused only the latter two effects. By expressing several mutated and truncated forms of Nep4 in transgenic animals, we show that the intracellular domain is responsible for the observed phenotypes while catalytic activity of the enzyme was apparently dispensable. A yeast two-hybrid screen identified a yet uncharacterised carbohydrate kinase as a first interaction partner of the intracellular domain of Nep4. CONCLUSIONS: These data demonstrate that the physiological significance of Nep4 is not limited to its function as an active peptidase but that the enzyme's intracellular N-terminus is affecting muscle integrity, independent of the protein's enzymatic activity. To our knowledge, this is the first report of an intracellular Nep domain being involved in muscle integrity.

Drosophila metalloproteases in development and differentiation: the role of ADAM proteins and their relatives.

ADAM metalloproteases are membrane bound glycoproteins that control many biological processes during development and differentiation, mainly by acting as ectodomain sheddases. The Drosophila genome contains five genes that code for classical ADAM proteins which are characterized by a highly conserved domain structure with the respective catalytic domains facing the extracellular space. More than 50 genes encode related proteins such as those that have lost their primary enzymatic activity while retaining, e.g., their adhesive properties. The physiological relevance of many Drosophila ADAMs and their relatives is still unknown, however for others, a striking role during organogenesis and tissue maintenance has been demonstrated during the last few years. We have carried out genetic screenings combined with candidate approaches, aiming to identify new components involved in cardiogenesis and muscle differentiation. Herein we summarize our results with a particular focus on metalloproteases with known or potential roles in tissue differentiation.

The disintegrin and metalloprotease Meltrin from Drosophila forms oligomers via its protein binding domain and is regulated by the homeobox protein VND during embryonic development.

A Disintegrin And Metalloprotease (ADAM) proteins belong to the metzincin superfamily of metalloproteases that are known to play important roles in several physiological and developmental processes including myoblast fusion, tumor necrosis factor-α release or fertilization. They are characterized by a typical domain structure with a proteolytically active domain and the protein binding domains both facing the extracellular space. Regulatory mechanisms are largely unknown. Here we report on the potential of the Drosophila ADAM Meltrin to form oligomers via its substrate binding domain. Significantly, oligomerization occurs apparently in a redox-dependent manner. Further analysis revealed that the ACR domain is responsible for aggregation while the disintegrin-like and EGF-like domains are not capable of oligomer formation. Stage dependent transcript analysis revealed a constant expression of three different splice variants, two of which were characterized by sequencing. Like many other ADAM proteins, Meltrin shows a highly restricted expression pattern during embryogenesis with at least two of the respective transcripts being present in a subpopulation of neuronal cells in the embryonic central nervous system. Finally, we report on the identification of the first regulator of meltrin: the homeobox protein ventral nervous system defective specifically excludes Meltrin expression from the embryonic ventral neuroectoderm.

Neprilysin 4, a novel endopeptidase from Drosophila melanogaster, displays distinct substrate specificities and exceptional solubility states.

Proteins belonging to the family of neprilysins are typically membrane bound M13 endopeptidases responsible for the inactivation and/or activation of peptide signaling events on cell surfaces. Mammalian neprilysins are known to be involved in the metabolism of various regulatory peptides especially in the nervous, immune, cardiovascular and inflammatory systems. Although there is still much to learn about their participation in various diseases, they are potential therapeutic targets. Here we report on the identification and first characterization of neprilysin 4 (NEP4) from Drosophila melanogaster. Reporter lines as well as in situ hybridization combined with immunolocalization demonstrated NEP4 expression during embryogenesis in pericardial cells, muscle founder cells, glia cells and male gonads. Western blot analysis confirmed the prediction of one membrane bound and one soluble isoform, a finding quite unusual among neprilysins with presumably strong physiological relevance. At least one NEP4 isoform was found in every developmental stage indicating protein activities required throughout the whole life cycle of Drosophila. Heterologously expressed NEP4 exhibited substrate preferences comparable to human neprilysin 2 with distinct cleavage of substance P and angiotensin I.