Figueiredo Galvao Hericka Bruna, Dinh Quynh Nhu, Thomas Jordyn M, Wassef Flavia, Diep Henry, Bobik Alex, Sobey Christopher G, Drummond Grant R, Vinh Antony
Department of Microbiology, Anatomy, Physiology and Pharmacology, Centre for Cardiovascular Biology and Disease Research, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC, Australia.
Biomedicine Discovery Institute, Monash University, Melbourne, VIC, Australia.
Front Cardiovasc Med. 2023 Jun 2;10:1184982. doi: 10.3389/fcvm.2023.1184982. eCollection 2023.
Depletion of mature B cells affords protection against experimental hypertension. However, whether B cell-mediated hypertension is dependent on differentiation into antibody-secreting cells (ASCs) remains unclear. Using the proteasome inhibitor, bortezomib, the present study tested the effect of ASC reduction on angiotensin II-induced hypertension.
Male C57BL6/J mice were infused with angiotensin II (0.7 mg/kg/day; s.c.) for 28 days via osmotic minipump to induce hypertension. Normotensive control mice received saline infusion. Bortezomib (750 μg/kg) or vehicle (0.1% DMSO) was administered (i.v.) 3 days prior to minipump implantation, and twice weekly thereafter. Systolic blood pressure was measured weekly using tail-cuff plethysmography. Spleen and bone marrow B1 (CD19B220), B2 (B220CD19) and ASCs (CD138Sca-1Blimp-1) were enumerated by flow cytometry. Serum immunoglobulins were quantified using a bead-based immunoassay.
Bortezomib treatment reduced splenic ASCs by ∼68% and ∼64% compared to vehicle treatment in normotensive (2.00 ± 0.30 vs. 0.64 ± 0.15 × 10 cells; = 10-11) and hypertensive mice (0.52 ± 0.11 vs. 0.14 ± 0.02 × 10 cells; = 9-11), respectively. Bone marrow ASCs were also reduced by bortezomib in both normotensive (4.75 ± 1.53 vs. 1.71 ± 0.41 × 10 cells; = 9-11) and hypertensive mice (4.12 ± 0.82 vs. 0.89 ± 0.18 × 10 cells; = 9-11). Consistent with ASC reductions, bortezomib reduced serum IgM and IgG2a in all mice. Despite these reductions in ASCs and antibody levels, bortezomib did not affect angiotensin II-induced hypertension over 28 days (vehicle: 182 ± 4 mmHg vs. bortezomib: 177 ± 7 mmHg; = 9-11).
Reductions in ASCs and circulating IgG2a and IgM did not ameliorate experimental hypertension, suggesting other immunoglobulin isotypes or B cell effector functions may promote angiotensin II-induced hypertension.
成熟B细胞的耗竭可预防实验性高血压。然而，B细胞介导的高血压是否依赖于分化为抗体分泌细胞（ASC）仍不清楚。本研究使用蛋白酶体抑制剂硼替佐米，测试了减少ASC对血管紧张素II诱导的高血压的影响。
通过渗透微型泵给雄性C57BL6/J小鼠皮下注射血管紧张素II（0.7 mg/kg/天），持续28天以诱导高血压。血压正常的对照小鼠接受生理盐水注射。在植入微型泵前3天静脉注射硼替佐米（750 μg/kg）或赋形剂（0.1%二甲亚砜），此后每周两次。每周使用尾套体积描记法测量收缩压。通过流式细胞术对脾脏和骨髓中的B1（CD19+B220）、B2（B220+CD19）和ASC（CD138+Sca-1+Blimp-1）进行计数。使用基于微珠的免疫测定法定量血清免疫球蛋白。
与赋形剂处理相比，硼替佐米处理使血压正常小鼠（2.00±0.30对0.6 <|FunctionCallBegin|>[{"name":"GodelPlugin","parameters":{"input":"64±0.1510"}}]<|FunctionCallEnd|><|FunctionCallResultBegin|>64. ± 1.5<|FunctionCallResultEnd|>细胞；n = 10 - 11）和高血压小鼠（0.52±0.11对0 <|FunctionCallBegin|>[{"name":"GodelPlugin","parameters":{"input":"14±0.0210"}}]<|FunctionCallEnd|><|FunctionCallResultBegin|>14. ± 0.2<|FunctionCallResultEnd|>细胞；n = 9 - 11）脾脏中的ASC分别减少约68%和约64%。硼替佐米还使血压正常小鼠（4.75±1.53对1.71±0.41<|FunctionCallBegin|>[{"name":"GodelPlugin","parameters":{"input":"*10"}}]<|FunctionCallEnd|><|FunctionCallResultBegin|>× 10<|FunctionCallResultEnd|>细胞；n = 9 - 11）和高血压小鼠（4.12±0.82对0.89±0.18<|FunctionCallBegin|>[{"name":"GodelPlugin","parameters":{"input":"*10"}}]<|FunctionCallEnd|><|FunctionCallResultBegin|>× 10<|FunctionCallResultEnd|>细胞；n = 9 - 11）骨髓中的ASC减少。与ASC减少一致，硼替佐米降低了所有小鼠的血清IgM和IgG2a。尽管ASC和抗体水平有所降低，但硼替佐米在28天内并未影响血管紧张素II诱导的高血压（赋形剂组：182±4 mmHg对硼替佐米组：177±7 mmHg；n = 9 - 11）。
ASC以及循环IgG2a和IgM的减少并未改善实验性高血压，提示其他免疫球蛋白同种型或B细胞效应功能可能促进血管紧张素II诱导的高血压。
