@misc{NaserKadowSchumacheretal.2021, author = {Naser, Eyad and Kadow, Stephanie and Schumacher, Fabian and Mohamed, Zainelabdeen H. and Kappe, Christian and Hessler, Gabriele and Pollmeier, Barbara and Kleuser, Burkhard and Arenz, Christoph and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander}, title = {Characterization of the small molecule ARC39}, series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {6}, issn = {1866-8372}, doi = {10.25932/publishup-51663}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-516635}, pages = {17}, year = {2021}, abstract = {Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90\%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM's catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.}, language = {en} } @article{NaserKadowSchumacheretal.2021, author = {Naser, Eyad and Kadow, Stephanie and Schumacher, Fabian and Mohamed, Zainelabdeen H. and Kappe, Christian and Hessler, Gabriele and Pollmeier, Barbara and Kleuser, Burkhard and Arenz, Christoph and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander}, title = {Characterization of the small molecule ARC39}, series = {Journal of Lipid Research}, volume = {61}, journal = {Journal of Lipid Research}, number = {6}, publisher = {American Society for Biochemistry and Molecular Biology}, address = {Bethesda}, issn = {1539-7262}, doi = {10.1194/jlr.RA120000682}, pages = {896 -- 910}, year = {2021}, abstract = {Inhibition of acid sphingomyelinase (ASM), a lysosomal enzyme that catalyzes the hydrolysis of sphingomyelin into ceramide and phosphorylcholine, may serve as an investigational tool or a therapeutic intervention to control many diseases. Specific ASM inhibitors are currently not sufficiently characterized. Here, we found that 1-aminodecylidene bis-phosphonic acid (ARC39) specifically and efficiently (>90\%) inhibits both lysosomal and secretory ASM in vitro. Results from investigating sphingomyelin phosphodiesterase 1 (SMPD1/Smpd1) mRNA and ASM protein levels suggested that ARC39 directly inhibits ASM's catalytic activity in cultured cells, a mechanism that differs from that of functional inhibitors of ASM. We further provide evidence that ARC39 dose- and time-dependently inhibits lysosomal ASM in intact cells, and we show that ARC39 also reduces platelet- and ASM-promoted adhesion of tumor cells. The observed toxicity of ARC39 is low at concentrations relevant for ASM inhibition in vitro, and it does not strongly alter the lysosomal compartment or induce phospholipidosis in vitro. When applied intraperitoneally in vivo, even subtoxic high doses administered short-term induced sphingomyelin accumulation only locally in the peritoneal lavage without significant accumulation in plasma, liver, spleen, or brain. These findings require further investigation with other possible chemical modifications. In conclusion, our results indicate that ARC39 potently and selectively inhibits ASM in vitro and highlight the need for developing compounds that can reach tissue concentrations sufficient for ASM inhibition in vivo.}, language = {en} } @phdthesis{Korovila2022, author = {Korovila, Ioanna}, title = {Role of proteolytic systems in lipotoxicity-induced hepatocellular damage}, doi = {10.25932/publishup-55238}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-552385}, school = {Universit{\"a}t Potsdam}, pages = {117}, year = {2022}, abstract = {Scope: Several studies show that excessive lipid intake can cause hepatic steatosis. To investigate lipotoxicity on cellular level, palmitate (PA) is often used to highly increase lipid droplets (LDs). One way to remove LDs is autophagy, while it is controversially discussed if autophagy is also affected by PA. It is aimed to investigate whether PA-induced LD accumulation can impair autophagy and punicalagin, a natural autophagy inducer from pomegranate, can improve it. Methods and results: To verify the role of autophagy in LD degradation, HepG2 cells are treated with PA and analyzed for LD and perilipin 2 content in presence of autophagy inducer Torin 1 and inhibitor 3-Methyladenine. PA alone seems to initially induce autophagy-related proteins but impairs autophagic-flux in a time-dependent manner, considering 6 and 24 h PA. To examine whether punicalagin can prevent autophagy impairment, cells are cotreated for 24 h with PA and punicalagin. Results show that punicalagin preserves expression of autophagy-related proteins and autophagic flux, while simultaneously decreasing LDs and perilipin 2. Conclusion: Data provide new insights into the role of PA-induced excessive LD content on autophagy and suggest autophagy-inducing properties of punicalagin, indicating that punicalagin can be a health-beneficial compound for future research on lipotoxicity in liver.}, language = {en} }