Characterization of the Inducible and Slow-Releasing Hydrogen Sulfide and Persulfide Donor P*: Insights into Hydrogen Sulfide Signaling

Abstract

Hydrogen sulfide (H2S) is an important mediator of inflammatory processes. However, controversial findings also exist, and its underlying molecular mechanisms are largely unknown. Recently, the byproducts of H2S, per-/polysulfides, emerged as biological mediators themselves, highlighting the complex chemistry of H2S. In this study, we characterized the biological effects of P*, a slow-releasing H2S and persulfide donor. To differentiate between H2S and polysulfide-derived effects, we decomposed P* into polysulfides. P* was further compared to the commonly used fast-releasing H2S donor sodium hydrogen sulfide (NaHS). The effects on oxidative stress and interleukin-6 (IL-6) expression were assessed in ATDC5 cells using superoxide measurement, qPCR, ELISA, and Western blotting. The findings on IL-6 expression were corroborated in primary chondrocytes from osteoarthritis patients. In ATDC5 cells, P* not only induced the expression of the antioxidant enzyme heme oxygenase-1 via per-/polysulfides, but also induced activation of Akt and p38 MAPK. NaHS and P* significantly impaired menadione-induced superoxide production. P* reduced IL-6 levels in both ATDC5 cells and primary chondrocytes dependent on H2S release. Taken together, P* provides a valuable research tool for the investigation of H2S and per-/polysulfide signaling. These data demonstrate the importance of not only H2S, but also per-/polysulfides as bioactive signaling molecules with potent anti-inflammatory and, in particular, antioxidant properties.

Polysulfides derived from the hydrogen sulfide and persulfide donor P* inhibit IL-1β-mediated inducible nitric oxide synthase signaling in ATDC5 cells: are CCAAT/enhancer-binding proteins β and δ involved in the anti-inflammatory effects of hydrogen sulfide and polysulfides?

“…For this reason, we aimed to clarify whether P* decreases nitrite levels via H2S release or its resulting mixture of per-& polysulfides. As we previously described [30], P* can quickly decompose to polysulfides in the presence of thiols, thereby providing a tool to differentiate between H2S-or polysulfides-mediated effects. Hence, we incubated ATDC5 cells for 1 h with freshly prepared P* (FR) or decomposed P* (ON) before 24 h of IL-1β-stimulation.…”

“…Regarding the biological effects of this compound, we previously reported that P* decreased IL-6 levels mainly dependent on H2S release in ATDC5 cells. P* further exerted antioxidative effects via Nrf2 and heme oxygenase-1 (HO-1) induction by polysulfide formation [30]. Additionally, in HeLa cells, polysulfides derived from P* decomposition inhibited caspase-3 activity [31].…”

“…We previously reported that P* exerted antioxidative effects and decreased IL-6 levels in ATDC5 cells [30]. To further elucidate the anti-inflammatory potential of P*, we examined the impact of P* on NO production.…”

Reactive sulfur species and their significance in health and disease

“…This compound generates a persulfide and a mixture of polysulfides as end-products. Moreover, it can also release H 2 S, but only in the presence of thiols, such as Cys-SH or GSH [ 195 ].…”

The antioxidant and oxidant properties of hydropersulfides (RSSH) and polysulfide species

“…The antioxidant properties of RSSH species have also been shown to protect against oxidative stress-mediated toxicity in myoblasts [ 31 ] and against myocardial ischemia-reperfusion injury [ 32 ]. Finally, an RSSH donor compound was found to possess potent anti-inflammatory and antioxidant properties in ATDC5 cells [ 33 ].…”