AP20187 is a synthetic dimerizer compound that can induce the dimerization of proteins engineered to contain FKBP (FK506-binding protein) domains[1]. AP20187 has been widely used in various biological research and therapeutic applications to control protein-protein interactions and regulate cellular processes[2]. By binding to FKBP domains, AP20187 can bring two proteins together, thereby activating or modulating specific signaling pathways or cellular functions[3]. This mechanism allows for precise control over biological processes, making it a powerful tool for studying complex cellular mechanisms and developing targeted therapies. AP20187 has shown significant potential in both cancer biology and regenerative medicine[4].
In vitro, treatment of HeLa cells modified with the iCasp9 gene with AP20187 (0.025–2.5nM) increased cell death in a concentration-dependent manner. Moreover, repeated treatments led to the development of resistance to AP20187[5]. In PC12 cells expressing the inducible trkA (ItrkA) receptor, AP20187 (1pM to 1.25μM) significantly induced neurite outgrowth in a time- and dose-dependent manner. AP20187 treatment also increased the phosphorylation levels of Erk1/2 and Akt in ItrkA-transduced PC12 cells to levels comparable to those induced by 50μg/mL nerve growth factor (NGF). Additionally, AP20187 treatment significantly increased neurite outgrowth by 3–4 times[6].
In vivo, 25- to 29-month-old INK-ATTAC transgenic mice were treated with AP20187 (10mg/kg) via intraperitoneal injection, three times per week for 8 weeks. AP20187 treatment significantly reduced the number of p16Ink4a-positive microglia in the CA3 region of the hippocampus and decreased microglial activation and inflammatory cytokine expression. AP20187 also improved cognitive function in aged mice, reducing the time and errors required to complete maze tests[7]. In 5- to 6-month-old INK-ATTAC transgenic mice, AP20187 (3.3mg/kg) was administered via intraperitoneal injection, three times per week for 4 weeks (total dose 40mg/kg). AP20187 treatment significantly decreased p16Ink4a expression in renal tissue, reduced the expression of senescence-associated genes (Cdkn2a, Cdkn2d, Cdkn1a), and lowered levels of proinflammatory cytokines and matrix metalloproteinases. AP20187 also improved renal function by reducing plasma creatinine levels, increasing renal blood flow and glomerular filtration rate, and reducing renal fibrosis and inflammatory cell infiltration[8].
References:
[1] Xiao H, Wang LL, Shu CL, et al. Establishment of a cell model based on FKBP12 dimerization for screening of FK506-like neurotrophic small molecular compounds. J Biomol Screen. 2006 Apr;11(3):225-35.
[2] Baker DJ, Childs BG, Durik M, et al. Naturally occurring p16(Ink4a)-positive cells shorten healthy lifespan. Nature. 2016 Feb 11;530(7589):184-9.
[3] Baker DJ, Wijshake T, Tchkonia T, et al. Clearance of p16Ink4a-positive senescent cells delays ageing-associated disorders. Nature. 2011 Nov 2;479(7372):232-6.
[4] Pathak S, Singh V, Kumar N, et al. Inducible caspase 9-mediated suicide gene therapy using AAV6 vectors in a murine model of breast cancer. Mol Ther Methods Clin Dev. 2023 Nov 24;31:101166.
[5] Yuan Y, Ren H, Li Y, et al. Cell-to-cell variability in inducible Caspase9-mediated cell death. Cell Death Dis. 2022 Jan 10;13(1):34.
[6] Alfa RW, Tuszynski MH, Blesch A. A novel inducible tyrosine kinase receptor to regulate signal transduction and neurite outgrowth. J Neurosci Res. 2009 Sep;87(12):2624-31.
[7] Ogrodnik M, Evans SA, Fielder E, et al. Whole-body senescent cell clearance alleviates age-related brain inflammation and cognitive impairment in mice. Aging Cell. 2021 Feb;20(2):e13296.
[8] Kim SR, Puranik AS, Jiang K, et al. Progressive Cellular Senescence Mediates Renal Dysfunction in Ischemic Nephropathy. J Am Soc Nephrol. 2021 Aug;32(8):1987-2004.