Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Nov 1;23(21):13364.
doi: 10.3390/ijms232113364.

The Organogermanium Compound 3-(Trihydroxygermyl) Propanoic Acid (THGP) Suppresses Inflammasome Activation Via Complexation with ATP

Junya Azumi  1 , Yasuhiro Shimada  1 , Tomoya Takeda  1 , Hisashi Aso  1   2 , Takashi Nakamura  1
Affiliations

The Organogermanium Compound 3-(Trihydroxygermyl) Propanoic Acid (THGP) Suppresses Inflammasome Activation Via Complexation with ATP

Junya Azumi et al. Int J Mol Sci. .

Abstract

Inflammasome activity is a key indicator of inflammation. The inflammasome is activated by pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs), which activate the p38-NF-κB pathway and promote IL-1β transcription (signaling step 1). Next, extracellular adenosine triphosphate (ATP) activates the inflammasome (a protein complex consisting of a signal recognition protein, an adapter protein, and Caspase-1) and secretion of inflammatory cytokines such as IL-1β (signaling step 2). Inflammasome activation causes excessive inflammation, leading to inflammasome-active diseases such as atherosclerosis and type 2 diabetes. A hydrolysate of the organogermanium compound Ge-132, 3-(Trihydroxygermyl) propanoic acid (THGP) can form a complex with a cis-diol structure. We investigated the inhibitory effect of THGP on inflammasome activity in human THP-1 monocytes. THGP inhibited IL-1β secretion and caspase-1 activation (signaling step 2) in an ATP-dependent manner. On the other hand, THGP did not suppress IL-1β secretion induced by only lipopolysaccharide (LPS) stimulation. In addition, as IL-6 is an ATP-independent inflammatory cytokine, THGP did not decrease its secretion. THGP also suppressed pyroptosis, which is a caspase-1 activity-dependent form of cell death. Therefore, THGP is expected to become a new therapeutic or prophylactic agent for inflammasome-associated diseases.

Keywords: Ge-132; THGP; inflammasome; inflammation; organogermanium.

PubMed Disclaimer

Conflict of interest statement

Junya Azumi, Yasuhiro Shimada, and Tomoya Takeda were employees of Asai Germanium Research Institute Co., Ltd. Hisashi Aso received remuneration from Asai Germanium Research Institute Co., Ltd. as an adviser. Takashi Nakamura received remuneration from Asai Germanium Research Institute Co., Ltd. as an officer. The results described in the paper were generated with funding from Asai Germanium Research Institute Co., Ltd.

Figures

Figure 1
Figure 1
The suppressive effect of THGP on the inflammasome via signaling step 2. (a) The secretion of IL-1β from THP-1 cells was measured by ELISA after stimulation with 10 μg/mL LPS, 5 mM ATP, or the combination of the two. THGP was added at a concentration of 0–12 mM. (b) The secretion of IL-1β from THP-1 cells was measured by ELISA after stimulation with 10 μg/mL LPS and 1 mM ATP. THGP was added at a concentration of 0–5 mM. (c) The secretion of IL-1β from RAW 264.7 cells was measured by ELISA after stimulation with 10 μg/mL LPS and 1 mM ATP. THGP was added at a concentration of 5 mM. (d) The effect of THGP on the mRNA expression of IL-1β in THP-1 cells treated with 10 μg/mL LPS and 5 mM THGP was investigated by real-time RT–PCR. (e) The secretion of IL-6 from THP-1 cells was measured by ELISA after stimulation with 10 μg/μL LPS and/or 5 mM ATP. THGP was added at a concentration of 5 mM. The mean and S.D. are shown. n = 6. ** p < 0.01.
Figure 2
Figure 2
The effect of THGP on caspase-1 expression in THP-1 cells. (a–c) The effect of THGP on the expression of Caspase-1 in THP-1 cells treated with or without 10 μg/mL LPS and 1 mM ATP was investigated by western blotting. β-Actin was used as an internal standard to quantify the expres-sion of each protein. (d) Caspase-1 activity in THP-1 cells treated with 10 μg/mL LPS, 1 mM ATP and/or 5 mM THGP was measured using a Caspase-Glo® 1 Inflammasome Assay Kit. (e) The effect of THGP on the mRNA expression of IL-1β in THP-1 cells treated with 10 μg/ml LPS and 5 mM THGP was investigated by real-time RT–PCR. The mean and S.D. are shown. n = 6. * p < 0.01, ** p < 0.05.
Figure 3
Figure 3
The inhibitory effect of THGP on inflammasome activity is dependent on ATP. The structural formulas and structures of ATP (a) and BzATP (b) and the estimated structure of the complex formed by ATP and THGP (c). (d) Complex formation between THGP and ATP or BzATP was investigated by 1H-NMR. (e) After stimulation with a combination of LPS with ATP or BzATP, the content of IL-1β secreted from THP-1 cells was measured by ELISA. The results and S.D. are shown. The mean and S.D. are shown. n = 6. ** p < 0.01.
Figure 4
Figure 4
Suppressive effect of THGP on pyroptosis induced by LPS/ATP. (a) The viability of THP-1 cells stimulated with 10 μg/mL LPS and 1 mM ATP was investigated using the MTS assay. (b) Cytotoxicity following LPS/ATP stimulation was investigated using the LDH assay. (c,d) The number of dead cells was determined by Hoechst/PI staining. Red and blue cells are dead (PI) and live cells (Hoechst), respectively (Scale bar: 100 μm). (e,f) The expression of caspase-3 was measured by western blotting. β-Actin was used as an internal standard to quantify the expression of each protein. The mean and S.D. are shown. n = 6. ** p < 0.01.
Figure 5
Figure 5
Mechanism by which THGP inhibits inflammasome activation induced by LPS/ATP. THGP suppresses the activity of Caspase-1 and the secretion of IL-1β by complexing with ATP in the presence of LPS/ATP. THGP also suppresses LPS/ATP-induced pyroptosis.
See this image and copyright information in PMC

References

    1. Gross O., Thomas C.J., Guarda G., Tschopp J. The Inflammasome: An Integrated View. Immunol. Rev. 2011;243:136–151. doi: 10.1111/j.1600-065X.2011.01046.x. - DOI - PubMed
    1. Guarda G., So A. Regulation of Inflammasome Activity: Regulation of Inflammasome Activity. Immunology. 2010;130:329–336. doi: 10.1111/j.1365-2567.2010.03283.x. - DOI - PMC - PubMed
    1. Kummer J.A., Broekhuizen R., Everett H., Agostini L., Kuijk L., Martinon F., van Bruggen R., Tschopp J. Inflammasome Components NALP 1 and 3 Show Distinct but Separate Expression Profiles in Human Tissues Suggesting a Site-Specific Role in the Inflammatory Response. J. Histochem. Cytochem. 2006;55:443–452. doi: 10.1369/jhc.6A7101.2006. - DOI - PubMed
    1. Arend W.P., Palmer G., Gabay C. IL-1, IL-18, and IL-33 Families of Cytokines. Immunol. Rev. 2008;223:20–38. doi: 10.1111/j.1600-065X.2008.00624.x. - DOI - PubMed
    1. Van de Veerdonk F.L., Netea M.G., Dinarello C.A., Joosten L.A.B. Inflammasome Activation and IL-1β and IL-18 Processing during Infection. Trends Immunol. 2011;32:110–116. doi: 10.1016/j.it.2011.01.003. - DOI - PubMed

MeSH terms