第一部分：右心血栓合并急性肺栓塞：一项中国的单中心经验

研究目的：右心血栓（Right heart thrombus, RHT）合并急性肺栓塞（Acute pulmonary embolism, APE）是一种罕见且危及生命的临床急症，尚无明确的管理指南。本文旨在探讨RHT-APE的患病率、临床特点及可能的危险因素，根据2019年ESC指南对肺栓塞严重程度进行分级，并分析RHT对不同危险分层的APE患者30天和90天全因死亡率的影响，总结本中心RHT-APE的治疗经验。

研究方法：这项观察性研究纳入了2015年9月至2019年8月在中国医学科学院阜外医院急诊确诊的17名RHT-APE患者和329名non-RHT-APE患者，收集患者的一般资料、生命体征、合并症和危险因素、基线实验室检查结果、经胸超声心动图指标以及治疗措施，并随访。

研究结果：APE中RHT的总患病率为4.91%，其患病率随APE危险分层的增高而增加。与non-RHT-APE患者相比，RHT-APE患者的血流动力学不稳定且心功能更差，危险分层水平更高，男性比例更高且更年轻。在调整了年龄和性别后，多因素logistic回归分析发现，高/中－高危分层、NT-proBNP>600pg/mL和右心室功能障碍是RHT的危险因素。Kaplan−Meier分析显示，non-RHT-APE患者的预后明显好于RHT-APE患者(30天生存率：log‐rank: P < 0.001；90天生存率：log‐rank: P = 0.002)。多因素logistic回归分析表明，RHT是影响APE患者30天死亡率的独立危险因素。亚组分析表明，即使在APE早期死亡风险高的患者中，RHT也会导致更差的预后。

研究结论：RHT增加APE患者30天和90天的死亡风险，应关注NT-proBNP> 600pg/mL、右心室功能障碍和危险分层高的年轻男性APE患者，以排除共存的RHT。

第二部分：PDGF经Akt1/2调控人肺动脉平滑肌细胞中钙通道蛋白STIM1的表达

研究目的：探讨血小板衍生生长因子（Platelet derived growth factor, PDGF）介导Akt1和Akt2在人肺动脉平滑肌细胞（Human pulmonary artery smooth muscle cells, hPASMCs）中对mTOR不同复合（mTORC1和mTORC2）和钙库操纵性通道（store-operated Ca²⁺ channel，SOC）的关键蛋白STIM不同亚型（STIM1和STIM2）的调控作用，及对hPASMCs增殖的可能影响。

研究方法：PDGF诱导体外培养的hPASMCs，CCK8法和Western Blot法检测PCNA蛋白水平以反映细胞增殖情况。Western Blot法检测Akt1、Akt2、p-Akt、Akt、mTOR、p-mTOR、raptor、rictor、STIM1、STIM2蛋白表达水平。siRNA干扰技术分别敲低Akt1和Akt2，Western Blot检测PCNA、p-mTOR、mTOR、raptor、rictor、STIM1、STIM2蛋白表达水平。

研究结果：（1）CCK8法和Western Blot法检测20ng/m PDGF显著诱导hPASMCs增殖。与对照组相比，PDGF组p-Akt、p-mTOR 蛋白表达水平显著增高（P均<0.0001），Akt2、raptor和STIM1蛋白水平显著增高（P均<0.01），而Akt1、rictor和STIM2蛋白表达水平无明显变化。（2）siRNA干扰技术分别敲低Akt1、Akt2后，mTOR和raptor蛋白表达水平均显著下降（P均＜0.0001），而rictor无显著变化；siRNA干扰技术敲低Akt1后，STIM1和STIM2蛋白表达水平均无显著变化，而敲低Akt2后STIM1蛋白表达水平显著下降（P＜0.05），STIM2无明显变化；且siRNA干扰技术敲低Akt2后PCNA蛋白表达水平有下降趋势，而siRNA干扰技术敲低Akt1后，PCNA蛋白表达水平无显著变化。

研究结论：PDGF通过激活Akt/mTOR上调Akt2/mTORC1信号通路，促进SOC关键蛋白STIM1表达进而诱导hPASMCs增殖；抑制Akt2/mTORC1信号通路降低SOC关键蛋白STIM1表达，可能减轻PDGF诱导的hPASMCs增殖。

Part1: Right heart thrombus in acute pulmonary embolism:

A single center experience in China

Research Objective: Right heart thrombus (RHT) in acute pulmonary embolism (APE) is a rare and life-threatening clinical emergency. There are no clear management guidelines. This study aimed to explore the prevalence, clinical characteristics and possible risk factors of RHT-APE. Grading the severity classification of pulmonary embolism according to 2019 ESC guidelines to analyze the effect of RHT on 30-day and 90-day mortality in patients with APE, and to summarize the treatment experiences of RHT-APE in our center.

Research Methods: This observational study included 17 RHT-APE patients and 329 non-RHT-APE patients diagnosed in the emergency department of Fuwai Hospital of the Chinese Academy of Medical Sciences from September 2015 to August 2019. The general data, vital signs, complications and risk factors, baseline laboratory results, transthoracic echocardiographic indicators and treatment measures were collected. Then all patients were followed up.

Research Results: The overall prevalence of RHT was 4.91% in APE. Its

prevalence increased along the increase of APE risk stratifications. Comparisons showed that with higher proportion of male gender and younger age, RHT‐APE patients also had worse hemodynamic instability and heart function, and higher risk stratification levels than non‐RHT‐APE patients. After adjusting by age and gender, multivariate logistic regression analysis found that high/medium-high risk stratification, NT-proBNP>600pg/mL and right ventricular dysfunction were risk factors for RHT. Kaplan−Meier analysis showed non‐RHT had better prognosis than RHT patients (30-day survival: log-rank: p<0.001; 90-day survival: log-rank: p=0.002). The multivariate logistic regression analysis showed RHT was an independent risk factor for 30-day mortality in APE. The subgroup analysis showed RHT would result in worse outcomes in patients who already had higher APE early mortality risk.

Research Conclusion: RHT would increase the risk of 30-day and 90-day mortality in APE. More attention should be paid to young male APE patients with NT-proBNP>600 pg/mL, right ventricular dysfunction, or high level of risk stratification, to exclude the coexistence of RHT.

Part 2: PDGF regulates the expression of calcium channel protein STIM1 via Akt1/2 in human pulmonary artery smooth muscle cells

Research Objective: To investigate the role of platelet derived growth factor (PDGF) -mediated Akt1 and Akt2 in different mTOR complexes (mTORC1 and mTORC2) and different subtypes of STIM (STIM1 and STIM2), the key proteins of store-operated Ca²⁺ channels （SOC）, and the possible influence on the proliferation of human pulmonary artery smooth muscle cells (hPASMCs).

Research Methods: PDGF induced hPASMCs cultured in vitro, CCK8 and Western Blot which detected PCNA protein levels were used to reflect cell proliferation. The protein expression levels of Akt1, Akt2, p-Akt, Akt, mTOR, p-mTOR, raptor, rictor, STIM1 and STIM2 were detected by Western Blot. siRNA interference technology was employed to knock down Akt1 and Akt2, and the protein expression levels of PCNA, mTOR, p-mTOR, raptor, rictor, STIM1 and STIM2 were detected by Western Blot.

Research Results: (1) The proliferation of hPASMCs was significantly induced by 20ng/mL PDGF by CCK8 and Western Blot. Compared with the control group, the protein expression levels of p-Akt and p-mTOR in PDGF group were significantly increased (P<0.0001), the protein levels of Akt2, raptor and STIM1 were significantly increased (P<0.01), while the protein expression levels of Akt1, rictor and STIM2 were not significantly changed.(2) After knockdown of Akt1 and Akt2 by siRNA, the expression levels of mTOR and raptor protein were significantly decreased (P<0.0001), while there was no significant change in rictor; After knockdown of Akt1, the expression levels of STIM1 and STIM2 were not significantly changed. The expression levels of STIM1 were significantly decreased by knockdown of Akt2 (P<0.05), bud did not change in STIM2. Moreover, the expression level of PCNA protein decreased after the knockdown of Akt2, while did not change significantly after the knockdown of Akt1.

Research Conclusion: PDGF induced the proliferation of hPASMCs by activating Akt/mTOR and up-regulating Akt2/mTORC1 signaling pathway which promoted the expression of SOC key protein STIM1. Inhibition of Akt2/mTORC1 signaling pathway reduced the expression of SOC key protein STIM1, which may reduce the proliferation of hPASMCs induced by PDGF.