Ryabov Vyacheslav V, Trusov Andrey A, Kercheva Maria A, Gombozhapova Aleksandra E, Ilyushenkova Julia N, Stepanov Ivan V, Fadeev Mikhail V, Syrkina Anna G, Sazonova Svetlana I
Department of Emergency Cardiology, Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk 634012, Russia.
Nuclear Medicine Department, Cardiology Research Institute, Tomsk National Research Medical Center, Russian Academy of Sciences, Tomsk 634012, Russia.
Biomedicines. 2024 Sep 25;12(10):2178. doi: 10.3390/biomedicines12102178.
Nuclear imaging modalities can detect somatostatin receptor type 2 (SSTR2) in vivo as a potential marker of local post-MI inflammation. SSTR2+ macrophages are thought to be the main substrate for SSTR-targeted radioimaging. However, the distribution of SSTR2+ cells in the MI patients' myocardium is unknown. Using immunohistochemistry, we investigated the distribution of SSTR2+ cells in the myocardium of patients who died during the MI inflammatory phase (n = 7) compared to the control group of individuals with fatal trauma (n = 3). Inflammatory cellular landscapes evolve in a wave front-like pattern, so we divided the myocardium into histological zones: the infarct core (IC), the border zone (BZ), the remote zone (RZ), and the peri-scar zone (PSZ). The number of SSTR2+ neutrophils (NPs), SSTR2+ monocytes/macrophages (Mos/MPs), and SSTR2+ vessels were counted. In the myocardium of the control group, SSTR2+ NPs and SSTR2+ Mos/MPs were occasional, SSTR2+ vessels were absent. In the RZ, the picture was similar to the control group, but there was a lower number of SSTR2+ Mos/MPs in the RZ. In the PSZ, SSTR2+ vessel numbers were highest in the myocardium. In the IC, the median number of SSTR2+ NPs was 200 times higher compared to the RZ or control group myocardium, which may explain the selective uptake of SSTR-targeted radiotracers in the MI area during the inflammatory phase of MI.
核成像模态可在体内检测生长抑素2型受体（SSTR2），作为心肌梗死后局部炎症的潜在标志物。SSTR2+巨噬细胞被认为是靶向SSTR的放射性成像的主要底物。然而，心肌梗患者心肌中SSTR2+细胞的分布尚不清楚。我们采用免疫组织化学方法，研究了在心肌梗死炎症期死亡的患者（n = 7）与致命创伤对照组（n = 3）心肌中SSTR2+细胞的分布。炎症细胞景观以波前样模式演变，因此我们将心肌分为组织学区域：梗死核心（IC）、边界区（BZ）、远隔区（RZ）和瘢痕周围区（PSZ）。对SSTR2+中性粒细胞（NP）、SSTR2+单核细胞/巨噬细胞（Mo/MP）和SSTR2+血管的数量进行计数。在对照组心肌中，SSTR2+NP和SSTR2+Mo/MP偶见，无SSTR2+血管。在远隔区，情况与对照组相似，但远隔区SSTR2+Mo/MP数量较少。在瘢痕周围区，心肌中SSTR2+血管数量最多。在梗死核心区，SSTR2+NP的中位数数量比远隔区或对照组心肌高200倍，这可能解释了在心肌梗死炎症期梗死区对靶向SSTR的放射性示踪剂的选择性摄取。
