Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: Experimental timeline. A, VCD-induced estrogen deficiency murine aneurysm model experiment timeline. VCD intraperitoneal (i.p.) injection was administered to 4-wk-old female C57BL/6 mice for 20 consecutive days, and mice were checked for menopause by Giemsa cytology stain at 52 d after initial injection. Only mice that were rendered menopausal by VCD were subjected to murine cerebral aneurysm induction. In these mice, the left common carotid artery and the right renal artery were ligated (Sx no. 1). 1 wk after the first surgery, porcine pancreatic elastase solution was injected into the right intraventricular space, and angiotensin II was continually infused at a dose of 1000 ng/kg/min via a subcutaneous osmotic pump (Sx no. 2). 3 wk postelastase injection, mice were sacrificed, and circle of Willis with or without aneurysms was harvested (Sx no. 3). Anti-mouse IL-6R antibody (100 μL, 200 μg/mL) or isotype-matched IgG control (100 μL, 200 μg/mL) i.p. injection was started 2 d prior to elastase injection and continued for 21 d. B, Ovariectomy-induced estrogen deficiency murine aneurysm model experiment timeline. Cerebral aneurysms were induced in 8-wk-old female C57BL/6 mice. The left common carotid artery and the right renal artery were ligated with simultaneous bilateral ovariectomy (Sx no. 1). 1 wk after the first surgery, porcine pancreatic elastase solution was injected into the right intraventricular space, and angiotensin II was then continually infused via a subcutaneous osmotic pump (Sx no. 2). At 3 wk, postelastase was injected, mice were sacrificed, and then the circle of Willis with or without aneurysms was harvested (Sx no. 3). Blood pressure (BP) recordings were performed at days 0 (baseline), 5, 15, and 27 after ligation. Anti-mouse IL-6R antibody (100 μL, 200 μg/mL) or isotype-matched IgG control (100 μL, 200 μg/mL) intraperitoneal injection was started 2 d prior to elastase injection and continued for 21 d.

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Injection, Staining, Control, Ligation

Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: Aneurysm formation and rupture rates in VCD-treated mice treated with anti-IL-6R antibody. A, We examined serum 17β-estradiol levels in VCD-treated (n = 3) and sesame oil vehicle-treated (n = 3) mice. Prior to the injection of VCD and sesame oil, there was no significant difference in serum 17-beta-estradiol between VCD-treated and vehicle-treated mice groups (Pre-VCD; VCD: 41.0 ± 0.1 pg/mL vs vehicle: 34.3 ± 3.5 pg/mL, P = NS); however, VCD-treated mice had lower serum 17-beta-estradiol levels at 52 d after injection of VCD (post-VCD, before induction of aneurysm; VCD: 20.5 ± 0.2 pg/mL vs vehicle: 61.3 ± 4.3 pg/mL, P = .004). This elevation in serum 17-beta-estradiol persists 1 wk after aneurysm induction (post-AN; VCD: 16.9 ± 0.6 pg/mL vs vehicle: 41.4 ± 4.2 pg/mL, P = .008). B, IL-6R neutralization with mouse anti-mouse IL-6 receptor antibody did not prevent cerebral aneurysm formation compared with isotype-matched IgG control in VCD-treated animals (IL-6R: 90.4% (19 of 21) vs IgG: 95% (20 of 21), P = NS). C, IL-6R neutralization with mouse anti-mouse IL-6 receptor antibody prevents cerebral aneurysm rupture compared with isotype-matched IgG control VCD-treated animals (IL-6R: 31.6% (6 of 19) vs IgG: 70.0% (14 of 20), *P = .026).

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Injection, Neutralization, Control

Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: Aneurysm formation and rupture rates in ovariectomized mice treated with anti-IL-6R antibody. A, IL-6R neutralization with mouse anti-mouse IL-6R antibody did not prevent cerebral aneurysms formation compared with isotype-matched IgG control in ovariectomized animals (IL-6R: 84.0% (21 of 25) vs IgG: 82.1% (23 of 28), P = NS). B, IL-6R neutralization with mouse anti-mouse IL-6R antibody prevents cerebral aneurysms rupture compared with control isotype-matched IgG control in ovariectomized animals (IL-6R: 28.6% (6 of 21) vs IgG: 65.2% (15 of 23), *P = .019).

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Neutralization, Control

Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: Aneurysm formation and rupture rates in wild-type mice treated with anti-IL-6R antibody. A, Aneurysm formation in 8-wk-old, wild-type female mice. There is no difference in aneurysm formation rate between anti-IL-6R antibody treatment and isotype-matched IgG control (anti-IL-6R: 76.2% (16 of 21) vs IgG: 76% (19 of 25), P = NS). B, Aneurysm rupture in 8-wk-old, wild-type female mice. There is no difference in aneurysm rupture rate between anti-IL-6R antibody treatment and isotype-matched IgG control (anti-IL-6R: 81.3% (13 of 16) vs IgG: 84.2% (16 of 19), P = NS). C, Aneurysm formation in 8-wk-old, wild-type male mice. There was no difference in aneurysm formation rate between anti-IL-6R antibody treatment and isotype-matched IgG control (anti-IL-6R: 64.7% (11 of 17) vs IgG: 71.4% (10 of 14), P = NS). D, Aneurysm rupture in 8-wk-old, wild-type male mice. There was no difference in aneurysm rupture rate between anti-IL-6R antibody treatment and isotype-matched IgG control (anti-IL-6R: 50% (5 of 10) vs IgG: 54.6% (5 of 11), P = NS).

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Control

Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: Blood pressure measurements in VCD and OVE mice. A, There was no difference in mean arterial blood pressure between IL-6R neutralized and IgG control mice in the VCD cohort: IL-6R neutralized mice (day 0, 93.0 ± 0.3 mmHg; day 5, 92.4 ± 0.3 mmHg; day 15, 109.4 ± 0.3 mmHg; day 27, 131.9 ± 0.8 mmHg) vs IgG control mice (day 0, 91.7 ± 0.7 mmHg; day 5, 91.4 ± 0.6 mmHg; day 15, 109.6 ± 0.4 mmHg; day 27, 123.3 ± 1.4 mmHg, P = NS) in VCD-treated estrogen deficiency model. B, There was no difference in mean arterial blood pressure between IL-6R neutralized and IgG control mice in the OVE cohort: IL-6R neutralized mice (day 0, 95.1 ± 0.3 mmHg; day 5, 99.5 ± 0.3 mmHg; day 15, 120.9 ± 0.9 mmHg; day 27, 141.2 ± 2.5 mmHg) vs IgG control mice (day 0, 93.9 ± 0.5 mmHg; day 5, 98.4 ± 0.4 mmHg; day 15, 122.1 ± 0.9 mmHg; day 27, 144.0 ± 1.5 mmHg, P = NS).

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Control

Journal: Neurosurgery

Article Title: Interleukin-6 Promotes Murine Estrogen Deficiency-Associated Cerebral Aneurysm Rupture

doi: 10.1093/neuros/nyz220

Figure Lengend Snippet: F4/80 immunofluorescence of cerebral aneurysms from estrogen-deficient and wild-type mice. A, Macrophages (F4/80 murine marker, red) are detected in and surrounding the arterial walls of IgG control-treated mice, B but not in anti-IL-6R-treated mice. C, Macrophage infiltration in anti-IL-6R-treated, estrogen-deficient female mice was significantly decreased, compared with IgG control-treated mice (1.9 ± 0.2 vs 5.7 ± 0.6 cells/2500 μm2; n = 15 vs n = 8; ***P < .001). D, Macrophage infiltration in IgG-treated and E anti-IL-6R-treated wild-type female mice. F, There is no difference in macrophage infiltration between anti-IL-6R-treated and IgG control wild-type female mice (1.9 ± 0.6 vs 2.5 ± 0.2 cells/2500 μm2: n = 9 vs n = 15; P = NS). DAPI (blue), autofluorescence (green). Scale Bar = 50 μ m.

Article Snippet: Mice were blindly randomized to receive intraperitoneal injection of mouse anti-mouse IL-6 receptor (IL-6R) antibody (Genentech, San Francisco, California; 20 μg/animal) or isotype-matched IgG control (mouse IgG2a; R&D Systems, MAB003, 20 μg/animal).

Techniques: Immunofluorescence, Marker, Control