Journal: iScience
Article Title: Robust GRK2/3/6-dependent desensitization of oxytocin receptor in neurons
doi: 10.1016/j.isci.2024.110047
Figure Lengend Snippet: GRK2/3/6 are required while β-arrestins are redundant for neuronal OXTR desensitization (A) Whole-cell recordings of sIPSC from dorsal LS neurons of β-arrestin-1 KO mice showing response to two applications of 200 nM TGOT for 1 min each separated by 15 min. Sample traces for baseline (black), first response (blue), and second response (magenta) (top) and summary graph of time course (bottom) are shown. The lack of robust second response compared to first indicates intact OXTR desensitization. (B) Whole-cell recordings of sIPSC from dorsal LS neurons of β-arrestin-2 KO mice showing response to two applications of 200 nM TGOT for 1 min each separated by 15 min. Sample traces (top) and summary graph of time course (bottom) are shown. The lack of robust second response compared to first indicates intact OXTR desensitization. (C) Schematic showing the strategy for CRISPR/Cas9-based KO of β-arrestin-1 in the LS of constitutive β-arrestin-2 KO mice. Inset shows expression of GFP from AAV GFP-Cre and AAV gRNA-Syn-GFP in the LS. Scale bar: 400 μm. (D) Immunohistochemical confirmation of CRISPR/Cas9-induced depletion of β-arrestin-1 in the LS. Sections were stained with antibody against GFP or β-arrestin-1 in control and injected animals. Scale bar: 100 μm. (E) Immunoblots on LS lysates from WT, β-arrestin-1 KO ( Arrb1 −/− ), β-arrestin-2 KO ( Arrb2 −/− ), and CRISPR/Cas9-induced β-arrestin-1 KO ( gArrb1 ) in β-arrestin-2 KO mice. Blots were stained with antibodies against β-arrestin-1, β-arrestin-2, and β-actin. (F) Whole-cell recordings of sIPSC from dorsal LS neurons of double β-arrestin KO mice showing response to two applications of 200 nM TGOT for 1 min each separated by 15 min. Sample traces (top) and summary graph of time course (bottom) are shown. The lack of robust second response compared to first indicates intact OXTR desensitization. (G) Whole-cell recordings of sIPSC from dorsal LS neurons in control condition (brown) and in the presence of CMPD101 (50 μM) and GRK6-IN-2 (50 μM) (blue). The summary graph of the time course of response to two applications of 200 nM TGOT for 1 min each separated by 15 min is shown (bottom). There is strong response to the second TGOT application in the presence of CMPD101 and GRK6-IN-2, indicating suppression of OXTR desensitization. Sample traces for CMPD101+GRK6-IN-2 condition are shown above the graph. (H) Bar graphs with baseline, first peak response, and second peak response in WT, β-arrestin-1 KO ( Arrb1 −/− ), β-arrestin-2 KO ( Arrb2 −/− ), double β-arrestin KO ( Arrb2 −/− + gArrb1 ), and GRK2/3/6 inhibition (CMPD101 + GRK6-IN-2). sIPSC frequency (Hz) WT: baseline, 2.920 ± 0.413; 1 st response, 13.100 ± 1.538; 2 nd response, 3.095 ± 0.314; n = 7 cells, 5 mice. sIPSC frequency (Hz) Arrb1 −/− : baseline, 4.136 ± 0.917; 1 st response, 12.590 ± 2.155; 2 nd response, 4.510 ± 1.003; n = 7 cells, 4 mice. sIPSC frequency (Hz) Arrb2 −/− : baseline, 2.813 ± 0.404; 1 st response, 13.150 ± 1.410; 2 nd response, 3.020 ± 0.277; n = 6 cells, 3 mice. sIPSC frequency (Hz) Arrb2 −/− + gArrb1 : baseline, 3.055 ± 0.486; 1 st response, 8.880 ± 1.342; 2 nd response, 3.927 ± 0.468; n = 10 cells, 6 mice. sIPSC frequency (Hz) CMPD101 + GRK6-IN-2: baseline, 2.600 ± 0.491; 1 st response, 15.410 ± 0.946; 2 nd response, 10.680 ± 1.506; n = 7 cells, 5 mice. The data in graphs are shown as mean ± SEM. ∗∗p < 0.01, ∗∗∗p < 0.001, ∗∗∗∗p < 0.0001, Repeated measures two-way ANOVA with post-hoc Tukey’s multiple comparisons test.
Article Snippet: Oxytocin (1910, Tocris), (Thr⁴,Gly⁷)-Oxytocin (TGOT) (4013837, Bachem), SR49059 (17972, Cayman Chemical, (d(CH 2 ) 5 1 ,Tyr(Me) 2 ,Arg 8 )-Vasopressin (3377,Tocris), FR900359 (UBO-QIC) (33666, Cayman Chemical) Tetrodotoxin (14964, Cayman Chemical) NBQX (14914, Cayman Chemical), Picrotoxin (P1675-5G, Sigma), Gallein (3090,Tocris), CMPD101 (26808, Cayman Chemical), Barbadin (HY-119706, MedChemExpress), GRK6-IN-1 (HY-142812, MedChemExpress), and GRK6-IN-2 (HY-142817, MedChemExpress) were purchased from vendors as indicated.
Techniques: CRISPR, Expressing, Immunohistochemical staining, Staining, Control, Injection, Western Blot, Inhibition