Surgery-induced cognitive impairment is prevented by concurrent administration of IL17A monoclonal antibody.

<p>Cognitive function was evaluated by Morris water maze (MWM) for 7 days after surgery and by a probe test on postoperative day 3 among mice treated with IL17A monoclonal antibody (SI) or IgG2a control (SC), surgery mice (SA) and control mice (C). (A) Swimming distance; (B) Swimming latency; (C) Time spent in the quadrant with the previously located hidden platform. (D) Spatial working memory was exmined by T maze. Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. SC3 group and #<i>P</i><0.05; ##<i>P</i><0.01 vs. SA3 group (n = 8).</p

Expression of IL17A and differentiation-related cytokines in the hippocampus following hepatectomy in mice.

<p>The mRNA and protein expression of IL17A, IL6, and TGFβ in hippocampus were measured by qRT-PCR and western blotting assay on postoperative days 1, 3, and 7. Surgery resulted in increased hippocampus mRNA and protein of IL17A (A), IL6 (B), and TGFβ (C) relative to mice receiving anesthesia alone or control mice. Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. C group at the corresponding time point. #<i>P</i><0.05; ##<i>P</i><0.01 vs. A group at the corresponding time point. Groups were as follows: C, control; A, anesthesia; SA, surgery plus anesthesia (n = 8).</p

Glial fibrillary acidic protein (GFAP) expression in the hippocampus following hepatectomy in mice.

<p>Representative bands of the hippocampus illustrating expression of GFAP from control group at 1 day (C1), 3 days (C3), and 7 days (C7); from anesthesia group at 1 day (A1), 3 days (A3), and 7 days (A7); or from surgery plus anesthesia group at 1 day (SA1), 3 days (SA3), and 7 days (SA7). Data are represented as the mean ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. C group at the corresponding time point. #<i>P</i><0.05; ##<i>P</i><0.01 vs. A group at the corresponding time point. Groups were as follows: C, control; A, anesthesia; SA, surgery plus anesthesia (n = 8).</p

Inhibition of TGFβ signaling blocks IL17A-stimulated co-expression of phospho-Smad2/3 (pSmad) with GFAP in mouse primary astrocytes.

<p>The administration of TGFβ receptor inhibitor (TβRI) reduced IL17A-induced pSmad 2/3 co-expression with GFAP in astrocytes. Double immunofluorescence staining showed that relative to IL17A (25 ng/ml) alone, pSmad 2/3 (red) co-localization with GFAP (green) in astrocytes following IL17A in combination with TβRI (5 μM) treatment was reduced. Magnification × 600.</p

Specific primer sequence for real-time PCR.

<p>Specific primer sequence for real-time PCR.</p

Mitigation of surgery-induced inflammation in mice by disabling or reducing IL17A signaling.

<p>Expression of IL-6 (A) and TGFβ (B) mRNA and protein in hippocampus was measured by qRT-PCR and western-blotting assay on postoperative day 3. (C) Expression of GFAP in hippocampus was measure by <b>i</b>mmunofluorescene assay (magnification ×400). (D) Histology of paraffin sections of hippocampus isolated from IgG2a control mice or mice with IL17A antibody ICV infusion <b>(</b>H&E magnification ×200<b>)</b> on day 3 after surgery. Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. SC3 group and #<i>P</i><0.05; ##<i>P</i><0.01 vs. SA3 group. Groups were as follows: C3, control; SC3, IgG2a control; SA3, surgery; SI3, IL17A monoclonal antibody treated (postoperative day 3, n = 8).</p

Blockade of IL17A inhibits TGFβ, phospho-Smad2/3 (pSmad2/3), APP, and Aβ_1–42 production in mouse primary astrocyte cultures.

<p>Primary astrocytes were treated with IL17A (25 ng/ml, named IL17 group), rabbit anti-mouse IGg2a (25 ng/ml, named IgG group), or IL17A plus IL17R siRNA (100nM, named IL17Rsi group) for 1, 24, or 48 h. The protein was assessed with Western blotting specific for TGFβ (A), pSmad2/3 (B), APP (C) and Aβ_1–42 (D). Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. IgG2a group at the corresponding time point. #<i>P</i><0.05; ##<i>P</i><0.01 vs. IL17 Rsi group at the corresponding time point.</p

Expression of APP, Aβ_1–42 protein, and phospho-Smad protein in the hippocampus following hepatectomy in mice.

<p>The mRNA and protein measurements of APP <b>(</b>A) and Aβ_1–42 (B) protein in hippocampus were made at 1 day (C1), 3 days (C3), and 7 days (C7) from control group; at 1 day (A1), 3 days (A3), and 7 days (A7) from anesthesia group or at 1 day (SA1), 3 days (SA3), and 7 days (SA7) from surgery plus anesthesia group. (C) phospho-Smad protein (pSmad) was detected by western blotting assay on postoperative day 3. Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. C group at the corresponding time point. #<i>P</i><0.05; ##<i>P</i><0.01 vs. A group at the corresponding time point. Groups were as follows: C, control; A, anesthesia; SA, surgery plus anesthesia (n = 8).</p

Performance in the hidden-platform Water Maze Test by hepatectomy surgery mice.

<p>The Morris water maze (MWM) was used to train mice for 5 days before surgery and to test memory formation changes for 7 days after surgery. (A) Latency to find the platform across testing days. (B) Latency to find the platform after surgery. (C) Swim speed across testing days. (D) Swim speed after surgery. (E) Distance to platform across testing days. (F) Distance to platform after surgery. (G) The probe test in the Morris water maze. Data are represented as means ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. C group at the corresponding time point. #<i>P</i><0.05; ##<i>P</i><0.01 vs. A group at the corresponding time point. Groups were as follows: C, control; A, anesthesia; SA, surgery plus anesthesia (n = 16).</p

Inhibition of TGFβ/Smad signaling blocks the IL17A-stimulated increase in TGFβ, phospho-Smad2/3 (pSmad2/3), and Aβ_1–42 levels in mouse primary astrocytes.

<p>Primary astrocytes were pre-treated for 30 min with TGFβ receptor inhibitor (TβRI, 5uM) then stimulated for 24 h with IL17A (25 ng/ml). Cells were harvested and analyzed for mRNA levels of TGFβ, pSmad2/3 by qRT-PCR, their proteins and Aβ_1–42 protein was detected by Western blotting in IL17A (named IL17 group) alone or in combination with TβRI (named TβRI group) treatment. A. TGFβ, B. pSmad2/3, C. Aβ_1–42. All data are the mean ± SEM. *<i>P</i><0.05; **<i>P</i><0.01 vs. IL17A group.</p