Gong Joyce, Chan Kyle S, Rajesh Amrita, Droho Steve, Lavine Jeremy A
Department of Ophthalmology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States.
Invest Ophthalmol Vis Sci. 2025 May 1;66(5):43. doi: 10.1167/iovs.66.5.43.
Effective therapies for treatment resistant neovascular age-related macular degeneration (nAMD) remain an unmet need. Beta-adrenergic receptor (AR) blockers can decrease laser-induced choroidal neovascularization (CNV) size in mice. We have shown that monocyte-derived macrophages (MDMs) and interleukin-6 (IL-6) are necessary for beta-AR blockers to inhibit CNV. However, the specific beta-AR and the mechanism of this pathway are not fully elucidated. We hypothesized that beta2-AR (Adrb2) signaling on MDMs increases IL-6 production and stimulates CNV.
Previously published single-cell RNA-sequencing data was reanalyzed to determine which mononuclear phagocytes express beta-ARs. Adrb2flox/flox: Cx3cr1CreER/+ mice (Adrb2ΔMacs) or Adrb2flox/flox (Adrb2flox) controls were given tamoxifen injections at either four weeks before or at the time of laser-induced CNV to knockout Adrb2 in tissue resident or all macrophages, respectively. Mice underwent laser induced-CNV, and eyes were collected for choroidal wholemount immunofluorescence imaging to measure CNV area, multiparameter flow cytometry to analyze macrophage heterogeneity, and ELISAs to quantitate IL-6 levels.
Adrb2 was the predominantly expressed beta-AR and was found on microglia, macrophages, and monocytes. Adrb2 deletion in tissue resident macrophages had no effect upon CNV area. Adrb2 deletion in all macrophages decreased CNV area by 1.4-fold. Adrb2ΔMacs posterior eye cups demonstrated similar levels of pro-angiogenic CD11c+ macrophages compared to Adrb2flox controls, but Ly6CnegCD11cneg macrophages were significantly increased. IL-6 levels increased with laser in Adrb2flox controls, but IL-6 levels in Adrb2ΔMacs posterior eye cups were unchanged.
Beta2-AR deletion in ocular-infiltrating macrophages decreases laser-induced CNV area. Beta2-AR expression regulates IL-6 expression in monocyte-derived macrophages.
对于难治性新生血管性年龄相关性黄斑变性（nAMD），有效的治疗方法仍有待满足。β-肾上腺素能受体（AR）阻滞剂可减小小鼠激光诱导的脉络膜新生血管（CNV）面积。我们已表明，单核细胞衍生的巨噬细胞（MDM）和白细胞介素-6（IL-6）是β-AR阻滞剂抑制CNV所必需的。然而，具体的β-AR及该途径的机制尚未完全阐明。我们推测，MDM上的β2-AR（Adrb2）信号传导会增加IL-6的产生并刺激CNV。
重新分析先前发表的单细胞RNA测序数据，以确定哪些单核吞噬细胞表达β-AR。分别在激光诱导CNV前四周或诱导时给Adrb2flox/flox:Cx3cr1CreER/+小鼠（Adrb2ΔMacs）或Adrb2flox/flox（Adrb2flox）对照注射他莫昔芬，以分别敲除组织驻留巨噬细胞或所有巨噬细胞中的Adrb2。对小鼠进行激光诱导CNV，收集眼睛进行脉络膜整体免疫荧光成像以测量CNV面积，进行多参数流式细胞术以分析巨噬细胞异质性，并进行酶联免疫吸附测定（ELISA）以定量IL-6水平。
Adrb2是主要表达的β-AR，在小胶质细胞、巨噬细胞和单核细胞上均有发现。组织驻留巨噬细胞中Adrb2的缺失对CNV面积没有影响。所有巨噬细胞中Adrb2的缺失使CNV面积减小了1.4倍。与Adrb2flox对照相比，Adrb2ΔMacs后眼杯显示出相似水平的促血管生成CD11c+巨噬细胞，但Ly6CnegCD11cneg巨噬细胞显著增加。在Adrb2flox对照中，IL-6水平随激光照射而升高，但Adrb2ΔMacs后眼杯中的IL-6水平未发生变化。
眼内浸润巨噬细胞中β2-AR的缺失可减小激光诱导的CNV面积。β2-AR的表达调节单核细胞衍生巨噬细胞中IL-6的表达。
