SRPK Inhibitor, SRPIN340

Toxicity: Standard Handling (A)

A cell-permeable isonicotinamide that acts as an ATP-competitive SRPK1-selective inhibitor (IC₅₀ = 0.14 and 1.8 µM, respectively, against mSRPK1 and mSRPK2) with much reduced activity against 143 other kinases. Shown to effectively counteract IGF-1-induced anti-angiogenic to pro-angiogenic VEGF isoforms switch both in cultures in vitro (1 h 10 µM SRPIN340 prior to 12 h IGF-1 stimulation of PCIPs) and in a murine hypoxia-induced retinal neovascularization model in vivo (10 pmol/µL/eye intraocular SRPIN340 injection) by inhibiting PKC/SRPK signaling-dependent, alternate splicing factor ASF- (SF2; splicing factor 2) mediated VEGF pro-mRNA PSS (proximal splice site) selection. Suppresses RNA virus Sindbis propagation (IC₅₀ = 60 µM in Vero cultures) and HCV-JFH1 replication (1 & 10 µM SRPIN340 in Huh7.5.1 cultures). Exhibits no toxicity toward rats (2 g/kg p.o. for 2 wks), CHO (5 mg/mL for 24 h), or Huh7 (30 µM for 48 h).

AA cell-permeable isonicotinamide compound that acts as an ATP-competitive (K_i = 0.89 µM using mSRPK1), SRPK1-selective inhibitor (IC₅₀ = 0.14 and 1.8 µM, respectively, against mSRPK1- or mSRPK2-catalyzed SF2 RS domain peptide phosphorylation) with much reduced or no activity against 143 other kinases, including Clk1 and Clk4, even at concentrations as high as 10 µM. Shown to effectively counteract IGF-1-induced anti-angiogenic to pro-angiogenic VEGF isoforms switch both in cultures in vitro (pro/anti VEGF mRNA ratio = 1.26- and 4.48-times of control ratio, respectively, in 12 h IGF-1 stimulated PCIPs with or without 1 h 10 µM SRPIN340 pretreatment) and in a murine hypoxia-induced retinal neovascularization model in vivo (Relative retinal VEGF mRNA content = 0.3 vs. 1.1, respectively, with or without 10 pmol/µL/eye intraocular SRPIN340 injection upon 48 h room air exposure of 6-day 75% O₂-adopted P12 neonatal mice) by inhibiting PKC/SRPK signaling-dependent, alternate splicing factor ASF- (SF2; splicing factor 2) mediated VEGF pro-mRNA PSS (proximal splice site) selection. Suppresses RNA virus Sindbis propagation (IC₅₀ = 60 µM as determined by virus titre in 4 d-infected Vero cultures) and HCV-JFH1 replication (% HCV core protein-positive Huh7.5.1 48 h post infection = 18.2, 5.9, and 3.0, respectively, with 0. 1. 10 µM SRPIN340; MOI = 0.1). Exhibits no mutagenic effects by Salmonella typhimurium AMES test, nor toxicity toward rats (2 g/kg p.o. for 2 wks), CHO (5 mg/mL for 24 h), or Huh7 (30 µM for 48 h).

Karakama, Y., et al. 2010. Antimicrob. Agents Chemother.54, 3179.
Nowak, D.G., et al. 2010. J. Biol. Chem.285, 5532.
Fukuhara, T., et al. 2006. Proc. Natl. Acad. Sci. USA103, 11329.

Packaged under inert gas

Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

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