Abstract Background: Early cancer detection and timely diagnosis are critical for improving patient outcomes and reducing healthcare costs. OncoSeek is an AI-driven, low-cost multi-cancer early detection (MCED) assay integrating seven protein tumor markers (PTMs) with clinical data, previously demonstrating 58.4% sensitivity, 92.0% specificity, and 70.6% tissue-of-origin accuracy in over 15,000 participants. Here, we present OncoSeek 2.0, an upgraded version that incorporates three additional PTMs to enhance the detection of prostate, lung, and squamous cell carcinomas, and evaluate its performance in validation cohorts and its expanded use for assisting cancer diagnosis in patients with tissue masses. Methods: OncoSeek 2.0 retained the original machine learning framework with expanded biomarker inputs. MCED performance was assessed in a retrospective cohort including 722 cancer and 355 non-cancer subjects. To further evaluate clinical utility, a prospective cohort of 732 patients with tissue masses, clinically deemed likely malignant and scheduled for surgery, was analyzed to assess the assay’s effectiveness in aiding cancer diagnosis. Results: Compared with OncoSeek 1.0, OncoSeek 2.0 achieved a higher AUC (0.934 vs. 0.888) and improved sensitivity from 70.4% to 83.5% at 90.1% specificity across 15 prespecified cancer types collectively accounting for 76.5% of global cancer mortality. Sensitivity gains were notable in lung (79.9% → 89.6%), prostate (58.8% → 94.1%), cervical (44.4% → 72.2%), and esophageal (41.6% → 64.4%) cancers. In the prospective tissue-mass cohort, OncoSeek 2.0 correctly identified 573 of 682 confirmed cancers (84.0% sensitivity). Across the same 15 cancer types, sensitivities exceeded 80% in 12, with slightly lower values observed in ovary (76.9%), breast (72.3%), and lymphoma (63.6%). Among the remaining 50 patients with pathologically confirmed benign lesions, 28 (56.0%) were correctly classified as non-cancer, potentially sparing them from unnecessary surgical procedures. Conclusion: OncoSeek 2.0 significantly improves sensitivity while maintaining high specificity and affordability (∼$30 reagent cost per test). The upgraded assay strengthens its utility for multi-cancer early detection and demonstrates validated diagnostic value in clinically suspected cancer cases. Its ability to correctly identify 84% of confirmed cancer cases in a tissue-mass cohort demonstrates meaningful diagnostic support to help prioritize patients needing confirmatory procedures. These findings position OncoSeek 2.0 as a practical and scalable solution for both population-level cancer early detection and real-world diagnostic support, particularly for cancers without USPSTF-recommended screening modalities or established non-invasive diagnostic pathways, where surgical procedures are commonly needed for definitive diagnosis. Citation Format: Mao Mao, Yong Shen, Shiyong Li, Wei Wu, Yinyin Chang, PingPing Xing, Chenyu Ding, Dandan Zhu, Qingxia Xu, Wei Cui. OncoSeek 2.0: An advanced multi-cancer blood test enhancing early detection and aiding cancer diagnosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1096.

10551 Background: Early identification of cancer remains essential for improving survival and reducing downstream treatment costs, yet effective and scalable multi-cancer screening strategies are still limited. OncoSeek is a previously validated, AI-based multi-cancer early detection (MCED) assay integrating protein tumor markers (PTMs) with clinical data, demonstrating 58.4% sensitivity, 92.0% specificity, and 70.6% tissue-of-origin accuracy in > 15,000 participants. To improve detection of specific cancer types and expand cancer-type coverage, we developed OncoSeek 2.0 by incorporating three additional PTMs and evaluated its performance in validation cohort. Methods: OncoSeek 2.0 retained the original machine-learning framework of OncoSeek 1.0, with expanded PTM inputs (ProGRP, SCCA, and tPSA). Performance was evaluated in a retrospective validation cohort comprising 1,267 cancer and 355 non-cancer individuals. Overall performance, including cancer-type-specific sensitivity, was assessed and compared with OncoSeek 1.0. Results: OncoSeek 2.0 incorporated three additional PTMs (ProGRP, SCCA, and tPSA) to enhance cancer-type–specific detection. ProGRP levels was significantly elevated in small cell lung cancer compared with other cancers and healthy controls; SCCA concentrations were higher in squamous cell carcinomas (esophageal, cervical, and lung) than in non-squamous cancers and controls; and tPSA was selectively increased in prostate cancer (all P < 0.0001). Compared with OncoSeek 1.0, OncoSeek 2.0 achieved a higher AUC (0.917 vs 0.860) and improved sensitivity from 65.3% to 77.6% at 90.1% specificity across 15 pre-specified cancer types collectively accounting for 76.5% of global cancer mortality. Sensitivity gains were notable in lung (75.1% → 84.3%), prostate (58.8% → 88.2%), cervical (55.6% → 65.6%), and esophageal (39.6% → 62.4%) cancers. When stratified by tumor stage, OncoSeek 2.0 achieved sensitivities of 54.2% for stage I, 71.7% for stage II, 79.8% for stage III, and 88.4% for stage IV, consistently outperforming OncoSeek 1.0, which achieved sensitivities of 30.2%, 53.8%, 62.3%, and 85.7% for stages I through IV, respectively. Conclusions: By integrating three additional cancer-type–specific PTMs, OncoSeek 2.0 substantially improves sensitivity while maintaining high specificity and low reagent cost (~$30 per test). The upgraded assay enhances detection across multiple tumor types and disease stages, with particularly pronounced gains in lung, prostate, cervical, and esophageal cancers. These results support OncoSeek 2.0 as a scalable and clinically actionable MCED approach for population-level early detection, particularly for cancers lacking USPSTF-recommended screening and in low- and middle-income countries.

Cancer is a critical global health issue, especially in low- and middle-income countries (LMICs). In this study, we integrated four additional cohorts to assess the performance and robustness of an AI-empowered blood-based test (named OncoSeek) for multi-cancer early detection (MCED). It included a case-control cohort of symptomatic cancer patients, a prospective blinded study, and two retrospective cohorts conducted on two distinct platforms. Combining these with previously published one training and two validation cohorts, we evaluated OncoSeek’s performance in 15,122 participants (3029 cancer patients and 12,093 non-cancer individuals) from seven centres in three countries, using four platforms and two sample types. OncoSeek showed adequate performance for MCED with an area under the curve (AUC) of 0.829, 58.4% sensitivity, 92.0% specificity, and overall accuracy of 70.6% in tissue of origin (TOO) prediction for the true positives. The test could detect 14 common cancer types, accounting for 72% of global cancer deaths, with sensitivities ranging from 38.9 to 83.3%. Additionally, the symptomatic cohort exhibited a high sensitivity of 73.1% at 90.6% specificity, indicating OncoSeek’s potential for cancer early diagnosis. These findings underscore OncoSeek’s consistent performances across diverse populations, platforms, and sample types, offering affordable and accessible multi-cancer early detection, especially for LMICs.

Approximately 30-40% of patients with diabetes develop diabetic kidney disease (DKD). Identifying decisive factors for DKD initiation is crucial. Here, we observed that glomerular podocytes in male and female patients with DKD and db/db mice specifically displayed BCAA catabolic defects. Podocyte-specific PP2Cm (a key BCAA catabolism enzyme) knockout or exogenous BCAA supplementation induced DKD phenotypes including podocyte dysfunction/apoptosis, glomerular pathology, and proteinuria in high-fat (HF)-diet-fed male mice. Mechanistically, BCAAs promoted PKM2 depolymerization and inactivation in podocytes. Depolymerized PKM2 suppressed glucose oxidative phosphorylation (OXPHOS), diverting glucose metabolism towards serine biosynthesis and folate metabolism. Depolymerized PKM2 is also co-transported with DDIT3 into the nucleus, acting as a co-transcriptional factor to enhance DDIT3 transcriptional activity, which promotes Chac1 and Trib3 expression and directly inducing podocyte apoptosis. Thus, BCAA catabolic defects may be one of the missing factors that determine DKD initiation. Targeting BCAA catabolism or PKM2 activation is a promising DKD prevention strategy.

Conventional cancer screening methodologies face significant challenges in resource-limited settings, constrained by high costs, technical complexity, and substantial infrastructure dependencies. These limitations critically restrict their implementation in low- and middle-income countries (LMICs). We present OncoSeek, a cost-effective multi-cancer early detection (MCED) blood test (reagent cost: $25), and evaluated its clinical performance across diverse populations. A multi-center study involving 15,122 participants (3,029 cancer/12,093 non-cancer) from Brazil, China, and the United States was conducted, divided into one training and six validation cohorts. Plasma/serum samples were analyzed for seven protein tumor markers (AFP, CA125, CA15-3, CA19-9, CA72-4, CEA, CYFRA 21-1) using Roche, Abbott, Luminex, and ELISA platforms in both retrospective and prospective cohorts. An artificial intelligence (AI)-driven algorithm integrated biomarker concentrations with age/sex data to differentiate cancer cases from non-cancer cases and predict tissue of origin (TOO). Furthermore, the fifth validation cohort (n=1,849 symptomatic patients: 1,031 cancer/818 non-cancer) expanded OncoSeek's diagnostic use, targeting symptomatic individuals requiring biopsy/surgical confirmation. Conventional single-threshold approaches exhibited cumulative false-positive rates with the increasing numbers of protein tumor markers (PTMs). In contrast, OncoSeek reduced false positives, achieving 93.0% specificity (vs. 54.3% with conventional methods) and 51.7% sensitivity in the training cohort. Robust performance persisted across all cohorts (pooled sensitivity: 58.4%; specificity: 92.0%; AUC range: 0.744–0.912) for 14 common cancer types, with sensitivities ranging from 38.9% to 83.3%. Sensitivity was observed to increase with advancing clinical stages: 42.8% at stage I, 52.1% at stage II, 61.9% at stage III, and 79.7% at stage IV. TOO prediction accuracy reached 65.4% among true positives. For symptomatic patients, OncoSeek demonstrated 73.1% sensitivity, 90.6% specificity, and an AUC of 0.845 in cancer diagnosis. OncoSeek outperforms traditional methods, showing robust performance across ethnicities, sample types, and platforms. Retrospective validation in symptomatic population supports its clinical utility for aiding decision-making. The accuracy of TOO prediction facilitates diagnostic workup. Mao Mao, Shen Yong, Xia Yong, Chang yin. yin, Xing ping. ping, Li Shi. yong, Wu Wei, Zhu Rui. dan, Zhong Guo. lin, Zhu Dan. dan, Raphael Brandão, Xu Qing. xia, Ji Ling. A cost-effective, blood-based multi-cancer detection test validated in a large-scale study across diverse sample types, platforms, and populations [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr C125.

10521 Background: Many established cancer screening or diagnostic methods often face challenges in low- and middle-income countries due to high cost, complexity, and reliance on extensive medical infrastructure. OncoSeek, a multi-cancer early detection (MCED) test developed with a panel of protein tumor markers (PTMs), is both affordable (reagent cost ~$20) and accessible, requiring only a blood draw. We evaluated its performance of multi-cancer detection and diagnosis in large-scale clinical studies. Methods: 15,122 participants (3,029 cancer vs 12,093 non-cancer) were divided into one training and six validation cohorts according to the different sites in three countries (Brazil, China, and United States). One tube of blood (plasma or serum) from each participant was collected and quantified using a panel of 7 PTMs (AFP, CA125, CA15-3, CA19-9, CA72-4, CEA, and CYFRA 21-1) through four common immunoassay platforms (Roche, Abbott, Luminex, and ELISA) in both retrospective and prospective settings. OncoSeek, utilizing artificial intelligence (AI) algorithm, was developed to differentiate cancer cases from non-cancer cases based on 7 PTM concentrations and clinical information including age and sex. It also predicted the potential affected tissue of origin (TOO). Furthermore, the fifth validation cohort, comprising 1849 patients (1031 cancer vs 818 non-cancer), was leveraged to broaden OncoSeek's application for cancer diagnosis. This cohort specifically targeted symptomatic patients, requiring further confirmation through biopsy or surgery. Results: The conventional clinical method, using a single threshold for each PTM, lead to accumulate the false positive rate with the growing number of PTMs. However, OncoSeek, empowered by AI, significantly reduced the false positive rate, elevating specificity from 54.3% to 93.0% and achieving an overall sensitivity of 51.7% in the training cohort. Performance remained robust (58.4% sensitivity and 92.0% specificity) across all seven cohorts, with area under the curve (AUC) values ranging from 0.744 to 0.912. The overall accuracy of TOO prediction was 65.4%. In the fifth cohort with symptomatic patients, OncoSeek achieved a 0.845 AUC for cancer diagnosis at 73.1% sensitivity and 90.6% specificity. Conclusions: OncoSeek significantly outperforms the conventional clinical method, showcasing its robust performance across various races, sample types, and platforms. The extensive retrospective assessment of OncoSeek in a symptomatic population demonstrates the feasibility of this MECD test in aiding clinicians for decision-making. Its accuracy of TOO facilitates the diagnostic workup.

Endophilin B1 is a member of the Endophilin family and has been shown to be involved in apoptosis, mitochondrial morphological changes and autophagy. Although Endophilin B1 is highly expressed in the heart, its role in the maintenance of normal cardiac function and myocardial ischemia and reperfusion (I/R) injury remains unclear. Here, we found that Endophilin B1 deletion provoked spontaneous cardiac contractile dysfunction, cardiac hypertrophy and fibrosis at 16 weeks of age. Moreover, at 8 weeks of age, although spontaneous cardiac dysfunction in Endophilin B1 deletion mice had not developed, the deletion of Endophilin B1 exacerbated I/R-induced cardiac contractile dysfunction and cardiomyocyte death, whereas restoration of Endophilin B1 expression in the heart reduced I/R injury. Furthermore, we discovered that Endophilin B1 is indispensable for maintaining normal mitochondrial structure and function. In addition, we found that Endophilin B1 is localized in extracellular mitochondrion-containing vesicles and is required for mitocytosis, a process by which damaged mitochondria are disposed through extracellular vesicles. In conclusion, our study identified Endophilin B1 as an essential mitocytosis regulator for maintaining mitochondrial homeostasis and cardiac function. These findings suggest that Endophilin B1 is a novel therapeutic target for cardiac disorders such as I/R injury, myocardial infarction and heart failure.

Abstract Cancer early detection aims at reducing cancer deaths. Unfortunately, many established cancer screening methods are not suitable for use in low- and middle-income countries (LMICs) due to cost, complexity, and dependency on extensive medical infrastructure. Nearly 10,000 participants (2003 cancer cases and 7888 non-cancer cases) were divided into one training and five independent validation cohorts across different races, sample types and platforms. One tube of peripheral blood was collected from each participant and quantified using a panel of seven protein tumor markers (PTMs) consisting of AFP, CA125, CA15-3, CA19-9, CA72-4, CEA and CYFRA 21-1 by common clinical immunoassay analyzers. An algorithm named OncoSeek was established using artificial intelligence (AI) to distinguish cancer cases from non-cancer cases by calculating the probability of cancer (POC) index based on the quantification of the seven PTMs and clinical information including sex and age, and to predict the possible affected tissue of origin (TOO). The conventional clinical method that relied only on a single threshold for each PTM would make a big problem when combining the results of those markers as the false positive rate would accumulate as the number of markers increased. Nevertheless, OncoSeek was empowered by AI to significantly reduce the false positive rate, increasing the specificity from 54.0% to 93.0%. The overall sensitivity of OncoSeek was 51.7%, resulting in 84.6% accuracy. The performance was consistent in the training and the five validation cohorts from three countries (Brazil, China and United States) including two sample types (plasma and serum) and three different platforms (Roche, Luminex and ELISA). The sensitivities ranged from 39.0% to 77.6% for the detection of the nine common cancer types (breast, colorectum, liver, lung, lymphoma, oesophagus, ovary, pancreas and stomach), which account for 59.2% of global cancer deaths annually. Furthermore, it has shown excellent sensitivity in several high-mortality cancer types for which there are lacking routine screening tests in the clinic, such as the sensitivity of pancreatic cancer was 77.6%. The overall accuracy of TOO prediction in the true positives was 65.4%, which could assist the clinical diagnostic workup. OncoSeek significantly outperforms the conventional clinical method, representing a novel blood-based test for multicancer early detection (MCED) that is non-invasive, easy, efficient and robust. Moreover, the accuracy of TOO facilitates the follow-up diagnostic workup. OncoSeek is affordable (~$20) and accessible requiring nothing more than a blood draw at the screening sites, which makes it adoptable in LMICs. Citation Format: Mao Mao, Bing Wei, Qingxia Xu, Yong Shen, Raphael Brandão, Shiyong Li, Wei Wu, Pingping Xing, Yinyin Chang, Dandan Zhu. Large-scale validaton studies of a blood-based effective and affordable test for multicancer early detection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1269.

AIMS:βII spectrin is a cytoskeletal protein known to be tightly linked to heart development and cardiovascular electrophysiology. However, the roles of βII spectrin in cardiac contractile function and pathological post-myocardial infarction remodelling remain unclear. Here, we investigated whether and how βII spectrin, the most common isoform of non-erythrocytic spectrin in cardiomyocytes, is involved in cardiac contractile function and ischaemia/reperfusion (I/R) injury. METHODS AND RESULTS:We observed that the levels of serum βII spectrin breakdown products (βII SBDPs) were significantly increased in patients with acute myocardial infarction (AMI). Concordantly, βII spectrin was degraded into βII SBDPs by calpain in mouse hearts after I/R injury. Using tamoxifen-inducible cardiac-specific βII spectrin knockout mice, we found that deletion of βII spectrin in the adult heart resulted in spontaneous development of cardiac contractile dysfunction, cardiac hypertrophy, and fibrosis at 5 weeks after tamoxifen treatment. Moreover, at 1 week after tamoxifen treatment, although spontaneous cardiac dysfunction in cardiac-specific βII spectrin knockout mice had not developed, deletion of βII spectrin in the heart exacerbated I/R-induced cardiomyocyte death and heart failure. Furthermore, restoration of βII spectrin expression via adenoviral small activating RNA (saRNA) delivery into the heart reduced I/R injury. Immunoprecipitation coupled with mass spectrometry (IP-LC-MS/MS) analyses and functional studies revealed that βII spectrin is indispensable for mitochondrial complex I activity and respiratory function. Mechanistically, βII spectrin promotes translocation of NADH:ubiquinone oxidoreductase 75-kDa Fe-S protein 1 (NDUFS1) from the cytosol to mitochondria by crosslinking with actin filaments (F-actin) to maintain F-actin stability. CONCLUSION:βII spectrin is an essential cytoskeletal element for preserving mitochondrial homeostasis and cardiac function. Defects in βII spectrin exacerbate cardiac I/R injury.

Mammalian mitochondrial DNA (mtDNA) encodes a total of 13 proteins, all of which are subunits of enzyme complexes of the oxidative phosphorylation. The mtDNA-encoded protein synthesis depends on the mitochondrial ribosomal proteins (MRPs), which assemble to form a specialized form of ribosome. Some mtDNA-encoded proteins have been reported to be reduced after myocardial ischemic injury. However, the molecular mechanisms responsible for this decrease and whether this decrease is involved in myocardial ischemia/reperfusion (I/R) injury remains unknown. Here, we found that the mtDNA-encoded protein levels were significantly decreased after I/R injury, while the mRNA levels of these genes were either increased or had no significant change. Subsequently, by querying and analyzing public database resources, we found that the expression of many mitochondrial translation-related proteins tended to decrease after myocardial infarction injury, and the reduction in the expression of these proteins was most obvious for Mrpl42. Furthermore, we found that cardiac Mrpl42 knockdown aggravated I/R-induced cardiac contractile dysfunction and cardiomyocyte death, while restoring Mrpl42 expression in the heart reduced I/R injury. Mrpl42 knockdown impaired the translation of mtDNA-encoded genes, ultimately led to aberrations in mitochondrial morphology and respiratory function. In addition, we found that the decrease in the expression of Mrpl42 after I/R injury was caused by the downregulation of Nrf2, which directly regulates Mrpl42 transcription. Our study revealed that ischemic downregulation of Mrpl42 expression and subsequent inhibition of mitochondrial translation contribute to cardiac I/R injury. Targeting Mrpl42 may be a novel therapeutic intervention for cardiac I/R injury and myocardial infarction.

The mitochondrial oxidative phosphorylation system is a major source of mitochondrial injury during myocardial ischemia and reperfusion. Mitochondrial ribosomal proteins (MRPs) assemble as specialized ribosomes to synthesize mtDNA-encoded proteins, which are subunits of enzyme complexes of the oxidative phosphorylation system. Some mtDNA-encoded proteins have been reported to be reduced after myocardial ischemic injury. However, the molecular mechanisms responsible for this decrease remain to be identified. Here, we found that many mitochondrial translation-related proteins showed a decreasing expression trend after MI injury, of which the reduction was most obvious in Mrpl42. Furthermore, we found that cardiac Mrpl42 knockdown aggravated I/R-induced cardiac contractile dysfunction, cardiomyocyte death and oxidative stress, while restoration of Mrpl42 expression in the heart reduced I/R injury. Mrpl42 knockdown impairs the translation of mtDNA-encoded genes, ultimately leading to aberrations in mitochondrial morphology and mitochondrial respiratory dysfunction. In addition, we found that the decreased expression of Mrpl42 after I/R injury was caused by the downregulation of NRF2 because NRF2 directly regulated Mrpl42 transcription. Our study identified that ischemic downregulation of Mrpl42 expression and subsequent inhibition of mitochondrial translation contribute to cardiac I/R injury via the suppression of mitochondrial function. Targeting Mrpl42 may be a novel therapeutic intervention against I/R injury and myocardial infarction.

目的 研究糖蛋白M6B（glycoprotein M6B,GPM6B）对巨噬细胞炎症因子IL-1β、TNF-α、IFN-γ和IL-6的影响。方法 （1）Western blot和qPCR检测RAW264.7经典激活的巨噬细胞（classically activated macrophage,M1）和替代激活的巨噬细胞（alternatively activated macrophage, M2）中GPM6B表达量变化。（2）分别用对照组（shScramble）和GPM6B干涉组（sh-GPM6B1和sh-GPM6B2）的慢病毒感染RAW264.7巨噬细胞系，荧光显微镜下观察病毒的感染效率。Western blot和qPCR检测GPM6B的干涉效率。（3）qPCR检测对照组和GPM6B干涉组促炎因子IL-1β、TNF-α和IFN-γ的mRNA表达水平，ELISA法检测上清中IL-1β和IL-6的含量。（4）Western blot检测干涉GPM6B后炎症相关分子p65和Iκα的磷酸化水平变化。结果 （1）相比于对照组，RAW264.7巨噬细胞M1型中GPM6B蛋白和mRNA水平均显著升高（P＜0.05），而M2型中GPM6B蛋白和mRNA水平均显著降低（P＜0.05）。（2）与sh-Scramble组相比，sh-GPM6B1组和sh-GPM6B2组GPM6B蛋白和m RNA水平均显著降低（P＜0.05）。（3）干涉GPM6B后促炎因子IL-1β、TNF-α和IFN-γ的m RNA表达水平和上清中IL-1β和IL-6均显著降低（P＜0.05）。（4）干涉GPM6B后炎症相关分子p65和Iκα的磷酸化水平降低。结论 干涉GPM6B可抑制RAW264.7巨噬细胞促炎因子的表达。

Mitochondrial calcium ([Ca2+]m) overload is considered a major trigger of cardiomyocyte death during myocardial ischemia/reperfusion (I/R) injury. Grpel2 is located in mitochondria and facilitates the mtHSP70 protein folding cycle in oxidative stress. However, Grpel2 expression during I/R injury and its impact on I/R injury remain poorly understood. This study explored the role of Grpel2 in I/R injury and its underlying mechanism. Mice were intramyocardially injected with recombinant adenovirus vectors to knockdown cardiac Grpel2 expression, and a myocardial I/R model was established. We confirmed that cardiac Grpel2 is upregulated during I/R injury. Cardiac-specific Grpel2 knockdown exacerbates mitochondrial fission, cardiomyocyte death and cardiac contractile dysfunction induced by I/R injury. Moreover, our study revealed that Grpel2 knockdown increased both MCU expression and [Ca2+]m content. Excessive mitochondrial fission and apoptosis were rescued by Ru360, an inhibitor of MCU opening. In summary, our findings suggest that Grpel2 alleviates myocardial ischemia/reperfusion injury by inhibiting MCU-mediated mitochondrial calcium overload and provide new insights into the mechanism of MCU-mediated [Ca2+]m homeostasis during I/R injury.

目的 研究血影蛋白βⅡ（Spectrin βⅡ）在棕榈酸诱导的小鼠原代心肌细胞DNA损伤和细胞凋亡中的作用。方法 （1）Western blot检测棕榈酸处理后小鼠原代心肌细胞Spectrin βⅡ表达量变化。（2）分别用Ad-shscramble（对照组）和Ad-sh-Spectrin βⅡ（Spectrin βⅡ干涉组）的腺病毒感染小鼠原代心肌细胞，荧光显微镜下观察病毒的感染效率。利用Western blot和qPCR检测Spectrin βⅡ的干涉效率。（3）Western blot检测棕榈酸处理后Ad-sh-scramble组和Spectrin βⅡ干涉组小鼠原代心肌细胞DNA损伤指标γ-H2AX及凋亡蛋白剪切型半胱天冬酶3（cleaved-caspase 3）的表达，采用流式细胞术检测各组细胞凋亡水平。结果 （1）给予棕榈酸处理的小鼠原代心肌细胞Spectrin βⅡ蛋白水平显著降低（P＜0.05）。（2）与Ad-sh-scramble组相比，Ad-sh-Spectrin βⅡ组Spectrin βⅡ的蛋白和mRNA水平均显著降低（P＜0.05）（3）给予棕榈酸处理后，与Ad-sh-scramble组相比，Ad-sh-Spectrin βⅡ组的γ-H2AX2和cleaved-caspase 3蛋白表达显著升高（P＜0.05），并且细胞凋亡率显著升高（P＜0.05）。结论 敲低Spectrin βⅡ加重棕榈酸诱导的小鼠原代心肌细胞DNA损伤和细胞凋亡。

目的研究糖蛋白M6B（Glycoprotein M6B,GPM6B）在白色脂肪细胞向棕色脂肪表型转变中的作用。方法 （1） Western blot和qPCR检测小鼠白色脂肪组织（white adipose tissue, WAT）和棕色脂肪组织（brown adipose tissue, BAT）中GPM6B的表达。（2）分别用对照组（shScramble）和敲低GPM6B组（shGPM6B1和shGPM6B2）的慢病毒液感染C3H10T1/2小鼠间充质细胞系,荧光显微镜下观察病毒的转染效率。Western blot和qPCR检测GPM6B的干涉效率。（3）将shScramble, shGPM6B1和shGPM6B2的稳转细胞系分别给予白色脂肪诱导分化液8 d,油红O染色观察脂滴形态,Western blot检测棕色脂肪标记基因解偶联蛋白（uncoupling protein, UCP1）的表达,qPCR检测热生成相关基因的mRNA表达。结果 （1）与WAT比,BAT中GPM6B的表达在蛋白和mRNA水平均显著降低（P＜0.05）。（2）与shScramble组相比,shGPM6B1组和shGPM6B2组GPM6B的干涉效率在蛋白和mRNA水平均显著降低（P＜0.05）。（3）敲低GPM6B后,白色脂肪细胞的脂滴变小,UCP1的表达和热生成相关基因的mRNA均显著升高（P＜0.05）。结论敲低GPM6B促进白色脂肪细胞向棕色脂肪表型转变。