目的 探究分泌型磷蛋白1（SPP1）和髓样分化因子88（MYD88）在二乙酰吗啡（DAM）致心肌凋亡中的作用。 方法 建立DAM成瘾SD大鼠动物模型，将12只SD大鼠随机分为NS组、DAM组，通过组织病理学检测方法，观察并比较两组大鼠心肌组织的形态学变化特征；通过TUNEL染色法观察各组心肌凋亡细胞数量；采用免疫组化检测SPP1和MYD88表达变化；RT-qPCR和Western blot检测SPP1、MYD88、Bcl2相关X蛋白（Bax）、B细胞淋巴瘤-2蛋白（Bcl2）、胱天蛋白酶（Caspase）-3、Caspase-9 mRNA和蛋白表达变化，同时Western blot检测活化的Caspase-3（Cleaved Caspase-3）和Cleaved Caspase-9蛋白表达变化；敲低原代SD大鼠乳鼠心肌细胞（NRCMs）SPP1表达，分组为CON组、DA组和shSPP1#3+DA组。采用CCK-8法检测NRCMs细胞活力；流式细胞术检测NRCMs细胞凋亡率。 结果 成瘾SD大鼠心肌组织HE染色和TUNEL染色显示：与NS组相比，DAM组肌原纤维丝局部出现断裂；凋亡细胞数量明显增加（P < 0.05）；RT-qPCR和Western blot结果显示：SPP1、MYD88、Bax、Caspase-3和Caspase-9 mRNA和蛋白表达均升高，同时Cleaved Caspase-3和Cleaved Caspase-9的蛋白表达水平增加，相反的是，Bcl2的mRNA和蛋白表达降低，差异均有统计学意义（P < 0.05）；DAM干预NRCMs后，与CON组相比，DA组的细胞活力明显降低（P < 0.05），凋亡率明显升高（P < 0.05），RT-qPCR和Western blot结果显示：DA组中SPP1、MYD88、Bax、Caspase-3和Caspase-9的mRNA和蛋白表达均升高（P < 0.05），同时Cleaved Caspase-3和 Cleaved Caspase-9的蛋白表达水平增加，Bcl2的mRNA和蛋白表达降低（P < 0.05），然而shSPP1#3+DA组与DA组相反（P < 0.05）。 结论 SPP1、MYD88在DAM诱导心肌细胞凋亡中发挥重要作用，降低SPP1的表达可降低DAM干预后心肌细胞的凋亡水平。

Objective To explore the role of secreted phosphoprotein 1 （SPP1） and myeloid differentiation primary response 88 （MYD88） in morphine-induced cardiomyocyte apoptosis. Methods A morphine addiction model was established in Sprague-Dawley （SD） rats. Twelve SD rats were randomly assigned to the normal saline （NS） group or the morphine-dependent （DAM） group. Histopathological analysis was employed to observe and compare myocardial tissue morphology between the two groups. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling （TUNEL） staining was performed to assess the number of apoptotic cells in each group. The expression levels of SPP1 and MYD88 were evaluated using immunohistochemistry. Quantitative real-time poly merase chain reaction （RT-qPCR） and Western blot were used to detect the mRNA and protein expression of SPP1， MYD88， Bax， Bcl2， Caspase-3， and Caspase-9. Simultaneously， Western blot analysis was used to detected the expression of Cleaved Caspase-3 and Cleaved Caspase-9 proteins. In vitro， SPP1 expression was knocked down in primary neonatal rat cardiomyocytes （NRCMs）， and cells were divided into three groups： control （CON）， morphine treated （DA）， and shSPP1#3 + DA. Cell viability was assessed using the CCK-8 assay， and apoptosis rates were determined by flow cytometry. Results HE and TUNEL staining of myocardial tissues from morphine-addicted SD rats revealed that， compared with the NS group， myofibrils in the DAM group exhibited partial disruption and a significant increase in apoptotic cells （P < 0.05）. Western blot and RT-qPCR analyses demonstrated that， relative to the NS group， the mRNA and protein levels of SPP1， MYD88， Bax， Caspase-3， and Caspase-9 were significantly upregulated in the DAM group （P < 0.05）， whereas Bcl2 expression was significantly downregulated at both mRNA and protein levels （P < 0.05）， and the protein expression levels of Cleaved Caspase-3 and Cleaved Caspase-9 were also increased. with all differences being statistically significant. In NRCMs following morphine intervention， cell viability in the DA group was markedly reduced compared to the CON group （P < 0.05）， accompanied by a significant increase in apoptosis rate （P < 0.05）. Consistently， Western blot and RT-qPCR results showed elevated mRNA and protein expression of SPP1， MYD88， Bax， Caspase-3， and Caspase-9 in the DA group （P < 0.05）， along with decreased Bcl2 expression （P < 0.05）. The protein expression levels of Cleaved Caspase-3 and Cleaved Caspase-9 were elevated simultaneously. In contrast， the shSPP1#3 + DA group exhibited opposing trends compared to the DA group， with statistically sig nificant differences （P < 0.05）. Conclusion SPP1 and MYD88 play critical roles in mediating morphine-induced cardiomyocyte apoptosis， and silencing SPP1 has been shown to significantly reduce the extent of cardiomyocyte apoptosis following morphine exposure.