Journal: Scientific Reports

Article Title: Emerging roles of SIRT1 activator, SRT2104, in disease treatment

doi: 10.1038/s41598-024-55923-8

Figure Lengend Snippet: Interaction of SRT2104 with SIRT1. ( A ) Detailed binding profile of SRT2104 to SIRT1. ( B ) Illustrative representation of the molecular interaction between SRT2104 and SIRT1. Molecular docking simulations were conducted utilizing AutoDock software to model the interaction. A grid box measuring 126 Å in each dimension was established, with a grid point spacing of 0.375 Å. During the simulations, the ligands were allowed to flex, whereas the protein's amino acid residues were held fixed. The calculated binding energy served as a measure of affinity. Visualization of the interaction was enhanced using PyMol and Discover Studio, revealing that SRT2104 occupies the hydrophobic pocket of SIRT1. The amine group of SRT2104 forms hydrogen bonds with Gly269, Gln320, and Glu512 in the SIRT1 structure. Additionally, an oxygen atom of SRT2104 engages in a hydrogen bond with ARG282, contributing to the stability of the interaction. Hydrophobic contacts are further augmented by interactions between SRT2104 and SIRT1's Pro271, Arg282, Phe312, Lys314, and Phe321, including Pi-Pi stacking and alkyl interactions. Van der Waals forces involving Ile270, Ile279, Leu283, Ile316, Phe388, Ile510, and Thr511 also play a vital role in sustaining the interaction's stability.

Article Snippet: NCT00937872 , I , 9 , Healthy Male Subjects between 18 and 65 years of age , A Clinical Study to Evaluate the Pharmacokinetics and the Absolute Bioavailability of SRT2104 Given as a 250 mg Oral Suspension and Intravenous Microdose of 100 μg Carbon-14 Radio-labeled SRT2104 in Healthy Male Subjects , 2008-11-22 to 2008-12-22 , Sirtris, a GSK Company , United Kingdom.

Techniques: Binding Assay, Software

Journal: Scientific Reports

Article Title: Emerging roles of SIRT1 activator, SRT2104, in disease treatment

doi: 10.1038/s41598-024-55923-8

Figure Lengend Snippet: Clinical trials involving SRT2104.

Article Snippet: NCT00937872 , I , 9 , Healthy Male Subjects between 18 and 65 years of age , A Clinical Study to Evaluate the Pharmacokinetics and the Absolute Bioavailability of SRT2104 Given as a 250 mg Oral Suspension and Intravenous Microdose of 100 μg Carbon-14 Radio-labeled SRT2104 in Healthy Male Subjects , 2008-11-22 to 2008-12-22 , Sirtris, a GSK Company , United Kingdom.

Techniques: Clinical Proteomics, Activity Assay, Capsules, Drug discovery, Suspension, Formulation

Journal: Scientific Reports

Article Title: Emerging roles of SIRT1 activator, SRT2104, in disease treatment

doi: 10.1038/s41598-024-55923-8

Figure Lengend Snippet: Schematic representation of the molecular mechanisms mediated by SRT2104. SRT2104, through the activation of SIRT1, orchestrates a network of molecular pathways, including P53, STAT3, ZKSCANS, AMPK, GR, GSK3β/PTEN, NF-κB, β-catenin/Runx2, MAPK, Smad7, FOXO, and TORC1. These interactions collectively contribute to the amelioration of conditions such as lung injury, diabetic vascular complications, diabetic nephropathy, cognitive impairments associated with diabetes, musculoskeletal disorders, brain ischemia–reperfusion injury, Parkinson's disease (PD) neurodegeneration, and optic nerve damage. Key: "→" denotes activation or promotion, "⊥" indicates inhibition, "red arrow up" signifies upregulation, "green arrow down" signifies downregulation, and "Ac" refers to deacetylation.

Article Snippet: NCT00937872 , I , 9 , Healthy Male Subjects between 18 and 65 years of age , A Clinical Study to Evaluate the Pharmacokinetics and the Absolute Bioavailability of SRT2104 Given as a 250 mg Oral Suspension and Intravenous Microdose of 100 μg Carbon-14 Radio-labeled SRT2104 in Healthy Male Subjects , 2008-11-22 to 2008-12-22 , Sirtris, a GSK Company , United Kingdom.

Techniques: Activation Assay, Inhibition

Journal: Scientific Reports

Article Title: Emerging roles of SIRT1 activator, SRT2104, in disease treatment

doi: 10.1038/s41598-024-55923-8

Figure Lengend Snippet: Overview of the potential effects of SRT2104 on various organ systems. The diagram illustrates the compound's impact on key physiological processes across different tissues. “↓”denotes a decrease or impairment, while “↑” signifies an increase or enhancement. This figure summarizes the multifaceted pharmacological actions of SRT2104, suggesting its potential therapeutic applications.

Article Snippet: NCT00937872 , I , 9 , Healthy Male Subjects between 18 and 65 years of age , A Clinical Study to Evaluate the Pharmacokinetics and the Absolute Bioavailability of SRT2104 Given as a 250 mg Oral Suspension and Intravenous Microdose of 100 μg Carbon-14 Radio-labeled SRT2104 in Healthy Male Subjects , 2008-11-22 to 2008-12-22 , Sirtris, a GSK Company , United Kingdom.

Techniques:

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Binding affinities (kcal/mol) of the compounds that were selected for further investigation.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques: Binding Assay, Protease Inhibitor

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Blind docking and docking of hypericin, SRT2104, and cyanidin-3-O-glucoside to the active site of the SARS-CoV-2 M pro dimer. Blind docking was performed using AutoDock Vina to produce 20 poses. Catalytic dyad residues His41 and Cys145 are highlighted in orange. Docking to the active site was performed using the QPLD protocol of Glide to each protomer of the M pro dimer.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques:

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Residue interactions between the M pro monomer and hypericin, SRT2104, and cyanidin-3-O-glucoside at 4.0 Å. Hydrogen bonds and π−π interactions are depicted by the yellow and cyan lines, respectively. The green residues are hydrophobic, the cyan residues are polar, and the red residues are negatively charged.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques: Residue

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Stability of SARS-CoV-2 M pro complex in the presence of hypericin, SRT2104, and cyanidin-3-O-glucoside. The protein-ligand complexes comprised of a single compound bound to the active site of each protomer of M pro , with cyanidin-3-O-glucoside depicted in purple (A) as an example. Average root mean square deviation (RMSD) for protein fit to backbone (B) for 100 ns, and average root mean square fluctuation of whole protein (C) following stabilisation. (D) shows the RMSF values the apo form subtracted from ligand bound forms of the protein. For the graphs (B – D), M pro in its apo form is shown in blue. M pro bound to hypericin, SRT2104, and cyanidin-3-O-glucoside is shown in red, green, and purple respectively.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques:

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Average energy contributions from MM-PBSA analysis were decomposed into a per-residue basis for binding of SARS-CoV-2 M pro with A) hypericin, B) SRT2104, and C) cyanidin-3-O-glucoside to the active site in protomer A (blue), and active site of protomer B (purple). Energy contributions were calculated in triplicate on 1000 ps segments of stabilised trajectories.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques: Residue, Binding Assay

Journal: Computational Biology and Chemistry

Article Title: Interaction of small molecules with the SARS-CoV-2 main protease in silico and in vitro validation of potential lead compounds using an enzyme-linked immunosorbent assay

doi: 10.1016/j.compbiolchem.2020.107408

Figure Lengend Snippet: Inhibition of M pro activity by small molecules. Percentage inhibition at a ligand concentration of 50 μM and IC 50 values calculated using an ELISA.

Article Snippet: The small molecule test inhibitors that we tested were hypericin (89 %, HWI pharma services GmbH, Germany), cyanidin-3-O-glucoside (reference standard, PhytoLab, Germany), SRT2104 and SRT1720 (>99 %, AdooQ® Bioscience, Irvine, CA, USA), resveratrol (>99 %), and l -sulforaphane (>95 %, Sigma-Aldrich, St Luis, MO, USA).

Techniques: Inhibition, Activity Assay, Concentration Assay, Enzyme-linked Immunosorbent Assay

Journal: Annals of Clinical and Translational Neurology

Article Title: Sirtuin 1 activator SRT2104 protects Huntington's disease mice

doi: 10.1002/acn3.135

Figure Lengend Snippet: SRT2104 ameliorated motor deficits and increased survival in N171-82Q HD mice. Mice were fed 0.5% SRT2104 containing diet from 6 weeks of age until the end of life. (A) Mice were trained on 11-mm cylindrical beam and then tested at 12, 18, and 24 weeks of age. The traverse time on the beam was recorded. The longer traverse time indicates impaired motor function. The values are the mean ± SE, two-way (group and age) repeated ANOVA tests were used. * P < 0.01 compared with the values of wild-type (WT) diet group; ** P < 0.05 compared with the values of HD diet group. n = 10–12 mice. (B) Body weight was recorded weekly. The values are the mean ± SE, n = 10–12 mice. (C) Survival was monitored daily by experienced operators. The mice were considered to be at the end of life when they were unable to right themselves after being placed on their backs and initiate movement after being gently prodded for 30 sec. n = 10–12 mice. Log rank analysis was used to compare survival data between two groups.

Article Snippet: SRT2104 was quantified in brain homogenate via LC/MS/MS at Alliance Pharma (Malvern, PA).

Techniques:

Journal: Annals of Clinical and Translational Neurology

Article Title: Sirtuin 1 activator SRT2104 protects Huntington's disease mice

doi: 10.1002/acn3.135

Figure Lengend Snippet: SRT2104 attenuated brain atrophy in N171-82Q mice. Mice were fed 0.5% SRT2104 containing diet from 6 weeks of age. Then, mice were anesthetized with isoflurane (1%), respiration was monitored and the temperature was maintained during the entire scan. Images were acquired by a three-dimensional T2-weighted fast spin echo sequence with the following parameters: echo time (TE)/repetition time (TR) = 40/700 msec, resolution = 0.1 × 0.1 × 0.1 mm, echo train length = 4, number of average = 2 and flip angle = 40°. The imaging resolution and contrast were sufficient for automatic volumetric characterization of the mouse brains and substructures. The intensity-normalized images were submitted by the Diffeomap software to a linux cluster, which runs Large Deformation Diffeomorphic Metric Mapping (LDDMM). The transformations encode morphological differences between subject and template images and can be analyzed with deformation-based morphometry (DBM) to detect regional changes in brain volume. Twenty-nine different brain regions were automatically segmented and the volume of each brain region was calculated. (A) Representative MRI images in mice from indicated groups. (B) The volumes of neocortex and striatum were measured by structural MRI at 22 weeks of age. Values are mean ± SE from four to six mice. * P < 0.05 compared with the WT control group; ** P < 0.05 compared with the HD control group (ANOVA with Holm–Sidak Post-hoc test).

Article Snippet: SRT2104 was quantified in brain homogenate via LC/MS/MS at Alliance Pharma (Malvern, PA).

Techniques: Sequencing, Imaging, Software, Control

Journal: American journal of hematology

Article Title: SIRT1 activates the expression of fetal hemoglobin genes

doi: 10.1002/ajh.24879

Figure Lengend Snippet: Small molecule SIRT1 activators induced HBG expression in erythroid progenitors from cord blood. Erythroid progenitors from cold blood were cultured in a two-phase system. On day 4 of erythroid differentiation phase (phase 2), the cells were treated with SRT2104 or SRT1720 at indicated concentration or vehicle control. The cells were collected on day 12 of phase 2 for mRNA analysis and on day 14 for F-cell and g-gloin protein analysis. (A) SIRT1 activator SRT2104 induces HBG mRNA. HBG mRNA is normalized to 18S. Error bars indicate SD. N = 4. (B) SIRT1 activator SRT1720 induces HBG mRNA. HBG mRNA is normalized to 18S. Error bars indicate SD. N = 4. (C) Effects of SIRT1 activators SRT2104 and SRT1720 on γ-globin protein levels. The ratio of γ-globin: β-actin protein is shown below the panel. (D) Mean change of F-cell in erythroid progenitor cells treated with SRT2104, compared with control cells from the same subject. Error bars indicate SD. N = 4. (E) Representative of Flow Cytometry profile showing SRT2104 increases F-cell proportions. (F) SIRT1 activators regulate SIRT1 deacetylase activity. The cells treated with SRT2104 at 2 uM or SRT1720 at 5 uM or vehicle control were collected on day 12 of phase 2, the cell lysates prepared and immunoblotted with anti-Ac-p53, p53 or β-actin antibodies [Color figure can be viewed at wileyonlinelibrary.com]

Article Snippet: Test compounds SRT2104 (APExBIO, Houston, TX) and SRT1720 (EMD Millipore, Billerica, MA) were added 4 days after initiation of the Phase 2 erythroid differentiation cultures.

Techniques: Expressing, Cell Culture, Concentration Assay, Control, Flow Cytometry, Histone Deacetylase Assay, Activity Assay

Journal: American journal of hematology

Article Title: SIRT1 activates the expression of fetal hemoglobin genes

doi: 10.1002/ajh.24879

Figure Lengend Snippet: Small molecule SIRT1 activators reactivated silenced HBG expression in adult erythroid progenitors. Erythroid progenitors from adult PBMC were cultured in a 2-phase culture system. On day 4 of erythroid differentiation phase (phase 2), the cells were treated with SRT 2104 or SRT1720 at indicated concentration or vehicle control. The cells were collected on day 12 of phase 2 for mRNA analysis and on day 14 for F-cell and γ-globin analysis. (A) SIRT1 activator SRT2104 and SRT1720 induced HBG mRNA in adult erythroid cells. HBG mRNA is normalized to HBG+HBB. *P < .05. Error bars indicate SD. N = 4. (B) Effects of SIRT1 activators SRT2104 and SRT1720 on γ-globin protein levels in adult erythroid cells. The ratio of γ-globin: β-actin protein is shown below the panel. (C) Mean change in proportions of cells expressing HbF in adult erythroid cells treated with SRT2104, compared with control cells from the same subject. Error bars indicate SD. N = 6. **P < .01 and *P < .05. (D) Representative of flow cytometric profiles showing SRT2104 increased F-cell proportions in adult erythroid cells [Color figure can be viewed at wileyonlinelibrary.com]

Article Snippet: Test compounds SRT2104 (APExBIO, Houston, TX) and SRT1720 (EMD Millipore, Billerica, MA) were added 4 days after initiation of the Phase 2 erythroid differentiation cultures.

Techniques: Expressing, Cell Culture, Concentration Assay, Control

Journal: American journal of hematology

Article Title: SIRT1 activates the expression of fetal hemoglobin genes

doi: 10.1002/ajh.24879

Figure Lengend Snippet: SIRT1 binding in the LCR and the HBG promoter, activated the HBG promoter and regulated LCR looping to the HBG promoter. (A) ChIP assay examining SIRT1 binding to the LCR and HBG promoter in K562 cells. Sonicated DNA from SIRT1 knockdown (shSIRT1) or scrambled shRNA infected K562 cells (Scrambled) was precipitated with anti-SIRT1 antibody or control IgG. The abundance of DNA precipitated with anti-SIRT1 antibody was normalized to that precipitated with IgG. Cont: internal control sequence. Error bars indicate SD, N = 3. (B) ChIP assay examining histone acetylation and Pol II binding in HBG promoter in K562 cells. Sonicated DNA from SIRT1 knockdown (shSIRT1) or scrambled shRNA infected K562 cells (Scrambled) was precipitated with anti-H3K9Ac, anti-H4K16Ac, and Pol II antibody or control IgG. The abundance of DNA precipitated with antibodies was normalized to that precipitated with IgG. Error bars indicate SD, N = 3. (C) SIRT1 knockdown in K562 cells decreased the looping of LCR to HBG promoter. 3C assay measuring crosslinking frequencies between the LCR and HBG or HBD in K562 cells expressing SIRT1 (scrambled) or SIRT1 knockdown cells (shSIRT1). The EcoRI fragment containing HS of the LCR (black bar) was used as the anchor region. Its crosslinking frequency with EcoRI fragments that contain HBG or HBD was assessed. Each 3C value was normalized to tubulin; The interaction frequencies between the anchor fragment and the fragment encompassing the HBG from the scrambled control sample were set to one. HBG or HBD are depicted on the bottom of the graph, with chromosomal position coordinates. The EcoRI digestion sites are depicted as black triangles. Error bars indicate SEM (n = 3). (D) SIRT1 activators decreased HBG suppressor gene expression. Erythroid progenitor cells from cord blood were treated with SRT2104 at day 4 of phase 2 and harvested for mRNA purification at day 12 of erythroid differentiation (phase 2). cDNA was synthesized and qRT-PCR were performed with primers for BCL11A, HDAC1, HDAC2 and KLF1. mRNA was normalized to 18S. Error bars indicate SD. N = 3

Article Snippet: Test compounds SRT2104 (APExBIO, Houston, TX) and SRT1720 (EMD Millipore, Billerica, MA) were added 4 days after initiation of the Phase 2 erythroid differentiation cultures.

Techniques: Binding Assay, Sonication, Knockdown, shRNA, Infection, Control, Sequencing, Expressing, Gene Expression, Purification, Synthesized, Quantitative RT-PCR

Journal: Scientific Reports

Article Title: SIRT1 activation by SRT2104 enhances mitophagy and reduces senescence in auditory cells

doi: 10.1038/s41598-026-37606-8

Figure Lengend Snippet: Effects of SRT2104 on cell viability, SIRT1 activity, and senescence- and mitophagy-related protein expression in HEI-OC1 cells. Cell viability was assessed in HEI-OC1 cells treated with various concentrations of SRT2104 (5–50 µM) for 24 h. No significant cytotoxic effects were observed at any concentration tested (A). HEI-OC1 cells were exposed to increasing concentrations of H₂O₂ for 1 h and subsequently incubated in fresh culture medium for 5 days. Cell viability decreased at an H₂O₂ concentration of 2 mM, consistent with growth arrest (One-way ANOVA, B). Cellular senescence was induced by exposing HEI-OC1 cells to 2 mM H₂O₂ for 1 h. SIRT1 activity was measured in H₂O₂-induced senescent cells with or without SRT2104 (20 µM) pre-treatment for 2 h. Pre-treatment with SRT2104 significantly enhanced SIRT1 activity compared to H₂O₂ treatment alone (Mann–Whitney U , C). Representative Western blot images showing the expression levels of p53, p21, LC3 (I and II), PINK1, Parkin, BNIP3, and SIRT1 in H₂O₂-induced senescent cells with or without pre-treatment of SRT2104 (5–20 µM) for 2 h (D). Quantitative analysis of Western blot data reveals that SRT2104 pre-treatment attenuated the expression of senescence markers (p53 and p21) and upregulated mitophagy-associated proteins (PINK1, Parkin, BNIP3, and LC3-II) (One-way ANOVA, E). Data are presented as mean ± standard error of the mean from five independent biological replicates ( n = 5). * p < 0.05, ** p < 0.01. The grouping of gels/blots were cropped from different parts of the same gel. Full-length blots are presented in Figure .

Article Snippet: The SIRT1 activator, SRT2104, was obtained from Merck (NJ, USA, Cat. # SML3754, Lot # 00003303359).

Techniques: Activity Assay, Expressing, Concentration Assay, Incubation, MANN-WHITNEY, Western Blot

Journal: Scientific Reports

Article Title: SIRT1 activation by SRT2104 enhances mitophagy and reduces senescence in auditory cells

doi: 10.1038/s41598-026-37606-8

Figure Lengend Snippet: Effects of SRT2104 on H₂O₂-induced cellular senescence and mitochondrial function in HEI-OC1 cells. Representative images of senescence-associated β-galactosidase (SA-β-gal) staining in HEI-OC1 cells treated with vehicle control, SRT2104 (20 µM) for 2 h, H₂O₂ (2 mM) for 1 h, or pre-treatment of SRT2104 (20 µM) for 2 h prior to H₂O₂ (2 mM) exposure. Blue staining indicates SA-β-gal–positive senescent cells (20X) ( A ). Quantification of SA-β-gal-positive cells revealed a significant reduction in the number of positive cells in the SRT2104 pre-treatment group compared to the H₂O₂-only group ( B ). Mitochondrial DNA (mtDNA) integrity was assessed by the ratio of long to short amplicons using quantitative PCR. SRT2104 pre-treatment significantly improved mtDNA integrity relative to H₂O₂-treated cells ( C ). Mitochondrial membrane potential was evaluated by JC-1 staining, and expressed as the red-to-green fluorescence intensity ratio. SRT2104 pre-treatment significantly increased the ratio, indicating improved mitochondrial polarization ( D ). Intracellular ATP levels were measured and expressed as a percentage of control values. ATP content was significantly preserved in SRT2104 pre-treated cells compared to those treated with H₂O₂ alone ( E ). SOD2 enzyme activity was assessed using a superoxide dismutase assay kit and expressed as the inhibition rate (%) of superoxide radicals. SOD2 activity was significantly preserved in SRT2104-pretreated cells compared with cells exposed to H₂O₂ alone ( F ). Data are presented as mean ± standard error of the mean from five independent biological replicates ( n = 5). Mann–Whitney U , * p < 0.05, ** p < 0.01.

Article Snippet: The SIRT1 activator, SRT2104, was obtained from Merck (NJ, USA, Cat. # SML3754, Lot # 00003303359).

Techniques: Staining, Control, Real-time Polymerase Chain Reaction, Membrane, Fluorescence, Activity Assay, Inhibition, MANN-WHITNEY

Journal: Scientific Reports

Article Title: SIRT1 activation by SRT2104 enhances mitophagy and reduces senescence in auditory cells

doi: 10.1038/s41598-026-37606-8

Figure Lengend Snippet: Effects of SRT2104 on the expression of senescence and mitophagy-related proteins in cochlear explants. Cochlear explants were treated with vehicle control, SRT2104 (20 µM) for 2 h, H₂O₂ (0.5 mM) for 5 h, or pre-treatment of SRT2104 (20 µM) for 2 h prior to H₂O₂ (0.5 mM) exposure. Representative western blot images showing the expression levels of p53, p21, LC3 (I and II), PINK1, Parkin, and SIRT1 in H₂O₂-induced senescent cochlear explants with or without pre-treatment of SRT2104 ( A ). Quantitative analysis of Western blot data reveals that SRT2104 pre-treatment attenuated the expression of senescence markers (p53 and p21) and upregulated mitophagy-associated proteins (PINK1, Parkin, and LC3-II) ( B ). Representative images of cochlear explants stained for senescence-associated β-galactosidase (SA-β-gal) activity. Blue staining indicates SA-β-gal–positive senescent cells (asterisks). OHCs: outer hair cells; IHCs: inner hair cells (20X) ( C ). SA-β-gal-positive cells were reduced in the SRT2104 pre-treatment group compared to the H₂O₂-treated group ( D ). Data are presented as mean ± standard error of the mean from five independent biological replicates ( n = 5). Mann–Whitney U , * p < 0.05, ** p < 0.01. The grouping of gels/blots cropped from different parts of the same gel. Full-length blots are presented in Figure S2.

Article Snippet: The SIRT1 activator, SRT2104, was obtained from Merck (NJ, USA, Cat. # SML3754, Lot # 00003303359).

Techniques: Expressing, Control, Western Blot, Staining, Activity Assay, MANN-WHITNEY

Journal: Scientific Reports

Article Title: SIRT1 activation by SRT2104 enhances mitophagy and reduces senescence in auditory cells

doi: 10.1038/s41598-026-37606-8

Figure Lengend Snippet: Effects of SIRT1 knockdown on SRT2104-induced anti-senescent and mitophagy-promoting activities in HEI-OC1 cells. HEI-OC1 cells transfected with either control siRNA (si-Control) or SIRT1-targeting siRNA (si-SIRT1) were treated with vehicle control, SRT2104 (20 µM) for 2 h, H₂O₂ (2 mM) for 1 h, or pre-treated with SRT2104 (20 µM) for 2 h prior to H₂O₂ (2 mM) exposure. Representative confocal images show the colocalization (yellow) of PINK1 (green) and Parkin (red) in si-Control and si-SIRT1 cells (100X) (A). Representative confocal images of cells stained with mitophagy detection dye (Mtphagy Dye, red) and lysosomal marker (Lyso Dye, green); colocalization appears in yellow (100X) (B). In si-Control H 2 O 2 -treated cells, SRT2104 pre-treatment significantly increased the colocalization of PINK1 and Parkin. This effect was markedly diminished in cells with siRNA-mediated SIRT1 knockdown (Mann–Whitney U , C). SRT2104 pre-treatment significantly increased Mtphagy/Lyso Dye colocalization, reflecting elevated mitophagic activity following H 2 O 2 treatment of si-Control HEI-OC1 cells. This increase was not observed in si-SIRT1-transfected cells (Mann–Whitney U , D). In si-Control H₂O₂-treated cells, SRT2104 pre-treatment significantly reduced the expression of senescence-associated proteins p53 and p21, while significantly increasing the levels of mitophagy-related proteins, including PINK1, Parkin, and LC3-II. These effects were notably suppressed following SIRT1 knockdown (One-way ANOVA, E, F). Data are presented as mean ± standard error of the mean from five independent biological replicates ( n = 5). * p < 0.05, ** p < 0.01. The grouping of gels/blots cropped from different parts of the same gel. Full-length blots are presented in Figure S3.

Article Snippet: The SIRT1 activator, SRT2104, was obtained from Merck (NJ, USA, Cat. # SML3754, Lot # 00003303359).

Techniques: Knockdown, Transfection, Control, Staining, Marker, MANN-WHITNEY, Activity Assay, Expressing