Circulating levels of soluble Dipeptidylpeptidase-4 are reduced in human subjects hospitalized for severe COVID-19 infections
Kristina Schlicht, Nathalie Rohmann, Corinna Geisler, Tim Hollstein, Carina Knappe, Katharina Hartmann, Jeanette Schwarz, Florian Tran, Domagoj Schunk, Ralf Junker, Thomas Bahmer, Philip Rosenstiel, Dominik M. Schulte, Kathrin Türk, André Franke, Stefan Schreiber, Matthias Laudes
Abstract
The recent outbreak of the corona virus COVID-19 in Wuhan, China, has spread globally resulting in an unprecedented threat of millions of human subjects all around the world [ 1 ]. Of interest, obesity and type 2 diabetes are stronger risk factors compared to chronic pulmonary diseases for a severe course of the infection with the need for intensive care treatment [ 2 ]. Indeed, cigarette smoking, known to cause pulmonary damage, might even be associated with milder forms of COVID-19 infections [ 3 ]. Beside evidence of metabolic diseases being risk factors for a severe disease course, observations from other corona-like virus outbreaks (SARS-CoV in 2002–2003 and MERS-CoV in 2012–2015) revealed long term metabolic complications even 12 years after acute infection in survivors [ 4 ]. Thus, molecular, cellular and clinical studies on the relation of COVID-19 and human metabolism might be important for both, to improve acute treatment of the infection and also to prevent long term metabolic complications of the millions of infected subjects worldwide. In the past it has been shown (1.) that membrane bound proteases like Dipeptidylpeptidase (DPP)-4 and Angiotensin Converting Enzyme (ACE)2 serve as binding partners for corona-like viruses to enter host immune cells [ 5 ] and (2.) that the circulating soluble form of DPP-4 (=sDPP-4) is reduced in MERS-CoV affected subjects [ 6 ]. Therefore, in the present study we examined circulating sDPP-4 serum concentrations in human COVID-19 patients compared to healthy controls in order to gain evidence, whether sDPP-4 could serve as a potential future target to improve acute and long-term COVID-19 metabolic comorbidities.