γ-secretase complex (specifically modulates γ42-secretase activity) [1]

Sulindac sulfide (100 μM) treatment may induce apoptosis in cells, which would lead to a marked decrease in the expression of all proteins and the generation of Aβ. Sulindac sulfide-secreting Aβ42 had an IC50 value of 30.6±2.8 μM. Up to 100 μM, neither Aβ40 nor Aβ42 secretion nor Notch cleavage was impacted by SSone or naproxen. Sulindac sulfide was found to inhibit γ42-secretase activity in a dose-dependent way. SSide has an IC50 value of 20.2±2.6 μM for blocking γ42 secretase activity in vitro. Sulindac sulfide is not an irreversible or pseudo-irreversible inhibitor, as seen by the slope of the rate versus enzyme concentration plotting decreasing with increasing SSide concentration. Moreover, γ-secretase activity was nearly fully restored when the dialyzed solubilized γ-secretase fraction was prepared with sulindac sulfide in comparison to CHAPSO buffer without sulindac sulfide. Based on these observations, it is highly likely that sulindac sulfide functions as a reversible γ-secretase inhibitor and that the γ-secretase complex is its actual molecular target [1].

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In N2a NL/N cells stably co-expressing βAPP NL and NotchAE, treatment with Sulindac Sulfide at 10-30 µM specifically decreased Aβ42 secretion, while Aβ40 secretion and Notch processing were unaffected. The IC50 value for Aβ42 secretion was 30.6 ± 2.8 µM. Treatment with 100 µM SSide caused cell death, leading to a marked decrease in both Aβ generation and total protein expression. [1]
In an in vitro γ-secretase assay using solubilized membrane fractions from HeLa cells and recombinant C100 substrate, Sulindac Sulfide directly inhibited γ42-secretase activity in a dose-dependent manner with an IC50 value of 20.2 ± 2.6 µM. At low concentrations (1-25 µM), it caused a transient but significant increase in Aβ40 generation, while at high concentrations (50-100 µM) it diminished both Aβ40 and Aβ42 generation. SSide also dose-dependently increased Aβ38 generation at low concentrations. [1]
In the same in vitro assay, Sulindac Sulfide displayed linear noncompetitive inhibition kinetics for γ42-secretase. The Km value remained constant while Vmax decreased with increasing SSide concentrations. [1]
In vitro, Sulindac Sulfide inhibited the generation of the APP intracellular domain (AICD-FmH) from the mutant C100 substrate (mt, which produces Aβ42) in a dose-dependent manner at 10-100 µM. For the wild-type substrate (wt, which produces Aβ40), AICD-FmH production was increased at 10-25 µM and completely inhibited at 100 µM. [1]
In vitro, the endoproteolytic cleavage of the Notch substrate (N102-FmH) to generate NICD-FmH was inhibited only by high concentrations of Sulindac Sulfide (250-500 µM) and was not affected at concentrations up to 100 µM. [1]

The γ-secretase enzyme source was prepared from HeLa cell membranes. Cells were homogenized, and membranes were pelleted by ultracentrifugation. The membrane pellet was then solubilized in a buffer containing CHAPSO. The solubilized membrane fraction was used as the enzyme source. For the assay, recombinant C100-FmH (wild-type or mutant, with a FLAG-myc-His tag) or N102-FmH substrates were incubated with the solubilized enzyme in a reaction buffer. After incubation (typically overnight at 37°C), the reactions were stopped, and the de novo generated Aβ species (Aβ40, Aβ42, Aβ38) or intracellular domain fragments (AICD-FmH, NICD-FmH) were quantitated by ELISA or analyzed by immunoblotting. To determine the inhibition mechanism, double-reciprocal plot analysis was performed using varying concentrations of the substrate and inhibitor to derive Km and Vmax values. [1]
To test for reversibility, the solubilized γ-secretase fraction was pre-incubated with 100 µM Sulindac Sulfide and then dialyzed against CHAPSO buffer without the inhibitor. The γ42-secretase activity was measured after dialysis. [1]
To study the interaction with a transition state analog, the γ42-secretase activity was measured in the presence of varying concentrations of Sulindac Sulfide and the active-site inhibitor L-685,458. The inhibition profile was analyzed via an intercept replot. [1]

N2a NL/N cells, which stably co-express βAPP NL (a Swedish mutant form of APP) and NotchAE (a truncated, constitutively active form of Notch), were used. Cells were cultured in media containing various concentrations of NSAIDs, including Sulindac Sulfide, for 24 hours. After treatment, the conditioned media were collected and analyzed for Aβ40 and Aβ42 levels using specific sandwich ELISA kits. For analysis of βAPP and Notch processing, cell lysates were prepared, separated by SDS-PAGE, and subjected to immunoblotting. βAPP and its C-terminal fragments were detected using the anti-βAPP antibody C4. Notch processing was assessed by detecting the Notch intracellular domain (NICD) using an anti-c-Myc antibody, as the NotchAE construct was c-Myc-tagged. [1]

[1]. Sulindac sulfide is a noncompetitive gamma-secretase inhibitor that preferentially reduces Abeta 42 generation. J Biol Chem. 2003 May 16;278(20):18664-70.

Sulindac sulfide is an aryl sulfide and a metabolite of sulindac. Sulindac is a nonsteroidal anti-inflammatory drug (NSAID) with anticancer activity. It functions as an NSAID, an apoptosis inducer, and an antitumor drug. Sulindac sulfide is an aryl sulfide, an organofluorine compound, and a monocarboxylic acid. It is functionally related to sulindac. Sulindac sulfide is the active metabolite of sulindac, a sulfinyl indene derivative with anti-inflammatory, analgesic, and antipyretic effects. Sulindac is a NSAID that works by inhibiting the cyclooxygenase (COX-1 and COX-2)-mediated conversion of arachidonic acid to pro-inflammatory prostaglandins. This drug may have a chemopreventive effect against colorectal cancer through a mechanism of inducing apoptosis. The sulfide metabolite is excreted via bile and reabsorbed by the intestine, thus helping to maintain stable blood concentrations and reduce gastrointestinal side effects. (NCI04)

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Epidemiological studies have indicated that long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) reduces the risk of Alzheimer's disease. This study identified that the NSAID Sulindac Sulfide directly inhibits γ-secretase activity, with a preferential effect on the generation of the highly amyloidogenic Aβ42 peptide. Notably, this effect is independent of its cyclooxygenase (COX)-inhibiting activity. [1]
The study suggests that Sulindac Sulfide acts as a reversible, noncompetitive γ-secretase inhibitor. Its inhibition profile is distinct from other γ-secretase inhibitors, as it preferentially reduces Aβ42 generation and has a weaker effect on Notch processing, which is a common side effect concern for other γ-secretase inhibitors. This differential activity suggests that it may be possible to develop derivatives that target APP cleavage without affecting Notch signaling. [1]

C20H17O2FS

340.41118

340.093

49627-27-2

Sulindac;38194-50-2;(E/Z)-Sulindac sulfide;32004-67-4;Sulindac sulfide-d3;250608-66-3

5352624

Light yellow to yellow solid powder

1.3±0.1 g/cm3

526.3±50.0 °C at 760 mmHg

189-191ºC

272.1±30.1 °C

0.0±1.5 mmHg at 25°C

1.653

5.74

1

4

4

24

546

0

O=C(O)CC(C1=C/2C=CC(F)=C1)=C(C)C2=C\C3=CC=C(SC)C=C3

LFWHFZJPXXOYNR-MFOYZWKCSA-N

InChI=1S/C20H17FO2S/c1-12-17(9-13-3-6-15(24-2)7-4-13)16-8-5-14(21)10-19(16)18(12)11-20(22)23/h3-10H,11H2,1-2H3,(H,22,23)/b17-9-

2-[(3Z)-6-fluoro-2-methyl-3-[(4-methylsulfanylphenyl)methylidene]inden-1-yl]acetic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~50 mg/mL (~146.88 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.34 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.34 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)