Refine
Year of publication
- 2019 (2)
Document Type
- Article (2)
Language
- English (2)
Has Fulltext
- yes (2)
Is part of the Bibliography
- no (2)
Keywords
Institute
Background: Psoriasis is hallmarked by vascular dysfunction, arterial hypertension, and an increased risk for cardiovascular diseases. We have shown recently that skin-driven interleukin (IL)-17A expression promotes psoriasis-like disease in mice, and this is associated with vascular inflammation, vascular dysfunction, and hypertension. As an intensive risk-factor reduction is recommended for psoriasis patients, we aimed to elucidate the impact of the angiotensin II receptor type 1 (AT1) antagonist telmisartan in a mouse model of severe psoriasis-like skin disease.
Methods and Results: Elevated blood pressure measured by tail-cuff plethysmography in mice with keratinocyte-specific IL-17A overexpression (K14-IL-17Aind/+ mice) was significantly reduced in response to telmisartan. Importantly, vascular dysfunction, as assessed by isometric tension studies of isolated aortic rings, vascular inflammation measured by flow cytometry analysis of CD45+CD11b+ immune cells, as well as the increased peripheral oxidative stress levels assessed by L-012-enhanced chemiluminescence were not attenuated by telmisartan treatment of K14-IL-17Aind/+ mice, nor was the persisting skin inflammation.
Conclusion: We provide first evidence for an effective antihypertensive treatment in experimental psoriasis by AT1 blockade, but without any impact on vascular inflammation and dysfunction in our mouse model of severe psoriasis-like skin disease. This suggests that vascular function and inflammation in psoriasis might not be attenuated as long as skin inflammation persists.
Rhodopsin-based voltage imaging tools for use in muscles and neurons of Caenorhabditis elegans
(2019)
Genetically encoded voltage indicators (GEVIs) based on microbial rhodopsins utilize the voltage-sensitive fluorescence of all-trans retinal (ATR), while in electrochromic FRET (eFRET) sensors, donor fluorescence drops when the rhodopsin acts as depolarization-sensitive acceptor. In recent years, such tools have become widely used in mammalian cells but are less commonly used in invertebrate systems, mostly due to low fluorescence yields. We systematically assessed Arch(D95N), Archon, QuasAr, and the eFRET sensors MacQ-mCitrine and QuasAr-mOrange, in the nematode Caenorhabditis elegans ATR-bearing rhodopsins reported on voltage changes in body wall muscles (BWMs), in the pharynx, the feeding organ [where Arch(D95N) showed approximately 128% ΔF/F increase per 100 mV], and in neurons, integrating circuit activity. ATR fluorescence is very dim, yet, using the retinal analog dimethylaminoretinal, it was boosted 250-fold. eFRET sensors provided sensitivities of 45 to 78% ΔF/F per 100 mV, induced by BWM action potentials, and in pharyngeal muscle, measured in simultaneous optical and sharp electrode recordings, MacQ-mCitrine showed approximately 20% ΔF/F per 100 mV. All sensors reported differences in muscle depolarization induced by a voltage-gated Ca2+-channel mutant. Optogenetically evoked de- or hyperpolarization of motor neurons increased or eliminated action potential activity and caused a rise or drop in BWM sensor fluorescence. Finally, we analyzed voltage dynamics across the entire pharynx, showing uniform depolarization but compartmentalized repolarization of anterior and posterior parts. Our work establishes all-optical, noninvasive electrophysiology in live, intact C. elegans.