Deactivation of the mitochondrial pyruvate dehydrogenase complex (PDC) is important for the metabolic switching of cancer cell from oxidative phosphorylation to aerobic glycolysis. Studies examining PDC activity regulation have mainly focused on the phosphorylation of pyruvate dehydrogenase (E1), leaving other post-translational modifications largely unexplored. Here, we demonstrate that the acetylation of Lys 488 of pyruvate dehydrogenase complex component X (PDHX) commonly occurs in hepatocellular carcinoma, disrupting PDC assembly and contributing to lactate-driven epigenetic control of gene expression. PDHX, an E3-binding protein in the PDC, is acetylated by the p300 at Lys 488, impeding the interaction between PDHX and dihydrolipoyl transacetylase (E2), thereby disrupting PDC assembly to inhibit its activation. PDC disruption results in the conversion of most glucose to lactate, contributing to the aerobic glycolysis and H3K56 lactylation-mediated gene expression, facilitating tumor progression. These findings highlight a previously unrecognized role of PDHX acetylation in regulating PDC assembly and activity, linking PDHX Lys 488 acetylation and histone lactylation during hepatocellular carcinoma progression and providing a potential biomarker and therapeutic target for further development.
Humans ; Acetylation ; Carcinoma, Hepatocellular/genetics* ; Liver Neoplasms/genetics* ; Pyruvate Dehydrogenase Complex/genetics* ; Gene Expression Regulation, Neoplastic ; Animals ; Mice ; Cell Line, Tumor ; Protein Processing, Post-Translational ; Histones/metabolism* ; Disease Progression

Objectives:To investigate the genetic etiology of six adult patients with Dilated cardiomyopathy (DCM), and analyze the structure of the identified variants, for providing reference for the diagnosis of DCM.Methods:Six adult patients with DCM (patients 1-6) admitted to the Department of Cardiology of Zhumadian Central Hospital from January 2023 to December 2023 were recruited. Clinical data of the patients were retrospectively collected. And 3 mL of peripheral blood was collected from each patients. Pathogenic variants patients were detected by whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. The possible functional significance of the identified missense variants was evaluated using software including SIFT, PolyPhen-2 and Mutation Taster. Specific regions of the MYBPC protein encoded by the MYBPC3 gene from different species were aligned using Mutation Taster. The wild-type and mutant MYBPC proteins were constructed using homologous modeling software MODELLER v10.4 and three-dimensional structures were visualized using PyMOL software. The molecular interaction between MYBPC-C5 domain and myosin with or without the mutation was further analyzed using ZDOCK module in Discovery Studio 2019 software. Pathogenicity ratings for the detected variant sites were performed in accordance with the Standards and Guidelines for the Interpretation of Sequence variants by the American College of Medical Genetics and Genomics (ACMG) (hereafter referred to as the ACMG Guidelines). This study was reviewed and approved by the Ethics Committee of Zhumadian Central Hospital (Approval No. 2022092007). Results:The six DCM patients had typical symptoms of heart failure, and echocardiography showed whole-heart dilation and decreased ventricular wall motion. Left ventricular end-diastolic dimension (LVEDD) was 57-74 mm, left ventricular ejection fraction (LVEF) was 35%-43%, and left ventricular fractional shortening (LVFS) was 17%-28%. Variation in DCM related genes, the c. 98473A>T(p.Lys32825*) variation of the TTN gene and the c.1976T>C(p.Ile659Thr) variation of the MYBPC3 gene, were identified in two patients with DCM. Multiple software predicted that both mutations were deleterious. MYBPC3-Ile659Thr mutation affected the highly conserved residue within the C5 domain of MYBPC. Three-dimensional structural analysis of homologous modeling revealed the alterations in amino acid properties and interactions with surrounding amino acids caused by the MYBPC3-Ile659Thr mutation. Further molecular docking analysis showed that the Ile659Thr mutation altered both the hydrogen bond and salt-bridge interactions between the MYBPC-C5 domain and the ligand myosin. Conclusions:Two mutations associated with DCM were identified in this study. The abnormal conformation of the mutant protein further affected its interaction with the ligand myosin, resulting in the phenotype of DCM.

Objective:To investigate the diagnostic value of metagenomic next-generation sequencing (mNGS) for pyogenic spinal infections.Methods:A total of 255 patients diagnosed with pyogenic spinal infections were enrolled between September 2022 and September 2024 at Qingdao University Affiliated Hospital, Fuzhou Second General Hospital, First Affiliated Hospital of Nanchang University, Shandong University Affiliated Public Health Clinical Center, and the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Among them, 155 were male and 100 were female, with an average age of 62.5±14.2 years (ranging from 13 to 90 years). All patients had samples of infected tissue and/or pus collected for microbial culture and mNGS testing. The number, types, and positive rates of pathogens detected by microbial culture and mNGS were compared. Using culture results as the gold standard, receiver operating characteristic (ROC) curve analysis was performed for mNGS testing and the combined method of mNGS and microbial culture, calculating the area under the curve (AUC) and 95% CI. Results:All 255 cases were clinically diagnosed as pyogenic spinal infections, with 194 cases providing microbiological evidence. The most common Gram-positive bacterium was Staphylococcus aureus, while the most common Gram-negative bacterium was Escherichia coli. A total of 33 pathogenic microorganisms were detected by mNGS, while microbial culture detected 18 pathogenic microorganisms. The positive rate of mNGS was 72.2% (184 out of 255), which was significantly higher than that of 30.2% (77 out of 255) for microbial culture, showing a significant difference (χ 2=90.150, P<0.001); the positive rate of mNGS combined with microbial culture was 76.1% (194 out of 255) with significant difference compared to mNGS alone (χ 2=8.100, P<0.001). Among 178 culture-negative samples, the detection rate of mNGS was 65.7% (117 out of 178); among 77 culture-positive samples, the detection rate of mNGS was 87.0% (67 out of 77), and 97.0% (65 out of 67) of the detected pathogens matched the culture results at the species level. The AUCs of the ROC curves for mNGS testing and the combination of mNGS with microbial culture were 0.606 [95% CI (0.534, 0.678)] and 0.671 [95% CI (0.606, 0.736)], respectively, with significant differences compared to microbial culture ( P=0.007; P=0.007). Conclusions:mNGS demonstrates superior performance over conventional culture in identifying pathogens in pyogenic spinal infections. Moreover, combining mNGS with culture further improves diagnostic yield, supporting its integration into clinical practice.

Objective:To analyze the positioning error and the overall setup errors (OSEs) of patients undergoing gamma knife pain-free face mask fractionated treatment for head tumors based on kV orthogonal image guidance.Methods:A total of 58 patients who received image-guided fractionated gamma knife treatment for head tumors with a pain-free face mask at the Gamma Knife Treatment Center of Xi'an International Medical Center Hospital from July 1, 2022 to May 31, 2024 were included in the study. A kV-class orthogonal X-ray IGPS image-guided positioning system was used to collect positioning errors in three translational directions: left-right (X), anterior-posterior (Y), and head-foot (Z), as well as in three rotational directions: left-right (P), anterior-posterior (R), and head-foot ( Y) before correction. After online correction and combined with manual positioning verification, the corrected positioning errors were recalculated. The OSEs in translational and rotational directions were calculated before and after correction. The positioning errors in all six directions (X, Y, Z, P, R, Y) before and after correction were plotted. And the OSE scatter plots in translational and rotational directions were created accordingly. Errors in the six directions and OSEs in translational and rotational directions were compared. The OSEs in translational and rotational directions were analyzed across different age groups and genders. Results:The pre-correction positioning errors in the X, Y, Z, P, R, Y directions for patients were (0.45±1.54) mm, -0.96 (-1.70, -0.28) mm, 1.67 (-0.15, 3.07) mm, (0.70±1.60) °, 0.65 (0.30, 1.19) °, (0.59±0.87) °, and the post-correction positioning errors were (-0.02±0.18) mm, 0.15 (0.10, 0.21) mm, 0.06 (-0.04, 0.16) mm, (0.20±0.79) °, 0.42 (0.19, 0.78) °, (0.20±0.63) °. There were statistically significant differences between before and after correction ( t=2.30, P=0.025; Z=-5.43, P<0.001; Z=-4.10, P<0.001; t=2.56, P=0.013; Z=-3.21, P=0.001; t=3.21, P=0.002). The OSEs in translational (X, Y, Z) and rotational (P, R, Y) directions before correction were 3.07 (1.93, 4.35) mm, 1.90 (1.28, 2.66) °, and the OSEs after correction were 0.27 (0.21, 0.33) mm, 1.08 (0.70, 1.54) °, with statistically significant differences ( Z=-6.60, P<0.001; Z=-5.52, P<0.001). For patients aged 18-44 years, the OSEs in translational (X, Y, Z) and rotational (P, R, Y) directions before and after correction were 3.65 (1.62, 3.95), 0.21 (0.21, 0.31) mm, 3.25 (2.24, 3.96) °, 0.92 (0.59, 1.45) °; for patients aged 45-59 years, the OSEs were 3.57 (2.17, 5.22), 0.29 (0.22, 0.35) mm, 1.89 (1.30, 2.30) °, 1.08 (0.62, 1.51) °; for patients aged 60-74 years, the OSEs were 2.92 (1.74, 4.06), 0.24 (0.19, 0.35) mm, 2.16 (1.09, 2.95) °, 0.98 (0.78, 1.75) °; for patients aged 75-89 years, the OSEs were 3.24 (2.12, 4.37), 0.29 (0.22, 0.47) mm, 1.73 (1.01, 1.83) °, 0.60 (0.47, 1.51) °. There were no statistically significant differences in OSEs of translational and rotational directions before and after correction among the four age groups ( H=1.23, P=0.747; H=1.74, P=0.627; H=7.45, P=0.059; H=2.80, P=0.424). For male patients, the OSEs before and after correction in translational (X, Y, Z) and rotational (P, R, Y) directions were (3.19±1.59), 0.27 (0.27, 0.33) mm, 1.89 (1.27, 2.75) °, (0.84±0.59) °; for female patients, the OSEs were (3.22±1.99), 0.26 (0.25, 0.35) mm, 1.90 (1.34, 2.41) °, (1.04±0.46) °. There were no statistically significant differences in OSEs of translational and rotational directions before and after correction between genders ( t=-0.07, P=0.949; Z=-0.48, P=0.632; Z=-0.02, P=0.161; t=-2.80, P=0.424) . Conclusions:The image-guided system, which is based on the kV orthogonal X-ray stereoscopic imaging, can significantly reduce the positioning errors between fractions of pain-free face mask gamma knife treatment for head tumor patients and improve the positioning accuracy of the gamma knife through the dual verification process of "automatic correction and manual review".

Objective To find out whether photobiomodulation(PBM)can mitigate cognitive dysfunction caused by chronic stress by affecting levels of adenosine triphosphate(ATP)and adenosine receptors.Methods Twenty-four C57BL/6J mice were randomly divided into a control group,a stress group,and a treatment group.Chronic unpredictable mild stress was used to establish a mouse model of stress.Six weeks into modeling,the treatment group was subjected to one week of PBM interventions.Behavioral tests were conducted to observe behavioral changes in the mice.Western blotting(WB)was used to detect the expressions of A1,A2B,and A3 adenosine receptors in the hippocampus and prefrontal cortex of mice in the three groups.Twelve C57BL/6J mice were randomly divided into a control group and an intervention group.The intervention group received a week of PBM interventions and underwent behavioral testing.WB was used to detect the expression changes of A1,A2B,and A3 adenosine receptors in the hippocampus and prefrontal cortex in both groups.Immunofluorescence assay was adopted to detect the expression of c-Fos in the hippocampus of mice in the two groups.The ATP assay kit made by Beyotime Biotechnology Co.,Ltd.was used to measure changes in ATP contents in the hippocampus and prefrontal cortex tissues of mice.Cell experiments were conducted to verify the effect of PBM on intracellular ATP contents.Results Mice in the stress group covered a similar distance to the control group,but finished far fewer platform crossings.There was no significant difference between the treatment group and the control group in the number of times of platform crossings,but compared favorably with the stress group where the levels of adenosine receptors in the hippocampus and prefrontal cortex were lower,but were increased by PBM.After PBM interventions in normal mice,platform crossings were increased significantly compared to the control group.PBM also raised adenosine receptor levels and ATP contents in the hippocampus and prefrontal cortex,and increased hippocampal c-Fos expressions.In vitro,PBM elevated intracellular ATP levels.Conclusion PBM may improve chronic stress-induced cognitive dysfunction by regulating ATP levels and adenosine receptor expressions,thereby modulating neuronal responsiveness in the hippocampus.

OBJECTIVE: To investigate the genetic etiology of six adult patients with Dilated cardiomyopathy (DCM), and analyze the structure of the identified variants, for providing reference for the diagnosis of DCM. METHODS: Six adult patients with DCM (patients 1-6) admitted to the Department of Cardiology of Zhumadian Central Hospital from January 2023 to December 2023 were recruited. Clinical data of the patients were retrospectively collected. And 5 mL of peripheral blood was collected from each patient. Pathogenic variants of the patients were detected by whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. The possible functional significance of the identified missense variants was evaluated using software including SIFT, PolyPhen-2 and Mutation Taster. Specific regions of the MYBPC protein encoded by the MYBPC3 gene from different species were aligned using Mutation Taster. The wild-type and mutant MYBPC proteins were constructed using homologous modeling software MODELLER v10.4 and three-dimensional structures were visualized using PyMOL software. The molecular interaction between MYBPC-C5 domain and myosin with or without the mutation was further analyzed using ZDOCK module in Discovery Studio 2019 software. Pathogenicity ratings for the detected variant sites were performed in accordance with the Standards and Guidelines for the Interpretation of Sequence variants by the American College of Medical Genetics and Genomics (ACMG) (hereafter referred to as the ACMG Guidelines). This study was reviewed and approved by the Ethics Committee of Zhumadian Central Hospital (Approval No. 2022092007). RESULTS: The six DCM patients had typical symptoms of heart failure, and echocardiography showed whole-heart dilation and decreased ventricular wall motion, left ventricular end-diastolic dimension (LVEDD) was 59-74 mm, left ventricular ejection fraction (LVEF) was 35%-43%, and left ventricular fractional shortening (LVFS) was 17%-28%. Variations of the DCM related genes, including a c.98473A>T (p.Lys32825*) variation of the TTN gene and a c.1976T>C (p.Ile659Thr) variation of the MYBPC3 gene, were identified in two patients. Multiple software predicted that both mutations were deleterious. MYBPC3-Ile659Thr mutation affected the highly conserved residue within the C5 domain of MYBPC. Three-dimensional structural analysis of homologous modeling revealed the alterations in amino acid properties and interactions with surrounding amino acids caused by the MYBPC3-Ile659Thr mutation. Further molecular docking analysis showed that the Ile659Thr mutation altered both the hydrogen bond and salt-bridge interactions between the MYBPC-C5 domain and the ligand myosin. CONCLUSION Two mutations associated with DCM were identified in this study. The abnormal conformation of the mutant protein further affected its interaction with the ligand myosin, resulting in the phenotype of DCM.
Humans ; Cardiomyopathy, Dilated/genetics* ; Male ; Adult ; Female ; Carrier Proteins/chemistry* ; Middle Aged ; Mutation ; Exome Sequencing ; Mutation, Missense ; Retrospective Studies ; Myosin Binding Protein C

AIM:To investigate the protective effect of Shexiang-Tongxin dropping pills(STDP)against myo-cardial injury induced by coronary microembolization(CME)in rats,with a focus on the cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway.METHODS:Thirty-two Sprague-Dawley rats were randomly allocated into four groups using a random number table:sham group,CME group,STDP group,and RU.521 group,with 8 rats per group.A rat model of CME was established via the injection of embolic microspheres into the left ventricle.The rats in sham group received an equal volume of normal saline via left ventricular injection instead,those in STDP group were given STDP(40 mg/kg)by oral gavage once daily for 14 consecutive days before CME modeling,and those in RU.521 group were intraperitoneally injected with RU.521(5 mg/kg)once daily for 7 consecutive days before CME modeling.Echocardiography was performed to evaluate cardiac function 24 h after modeling.HE staining was used to observe pathological changes in myocardial tissue,and TTC staining was applied to detect myocardial infarction areas.Enzyme-linked immunosorbent assay(ELISA)was used to measure levels of interleukin(IL)-1β and tumor necrosis factor(TNF)-α.A commercial assay kit was employed to detect myocardial injury marker cardiac troponin I(cTnI).Western blot was performed to analyze the expression of cGAS-STING pathway-related proteins in cardiac tissues.RESULTS:Compared with sham group,the rats in CME group exhibited significantly impaired cardiac function and a marked increase in serum cTnI levels(P<0.05).In contrast,compared with CME group,the rats in both STDP group and RU.521 group demonstrated significant improvements in cardiac function and reductions in cTnI levels((P<0.05).Furthermore,HE staining and TTC staining revealed that the rats in CME group had loosely arranged myocardial fibers,swollen cardiomyo-cytes,and an increased myocardial infarction erea compared with sham group(P<0.05).Meanwhile,the expression lev-els of inflammatory factors IL-1β and TNF-α,as well as the relative expression of cGAS,STING and NF-κB p-p65 pro-teins were significantly increased(P<0.05).In comparison,the rats in STDP group and RU.521 group showed a signifi-cant reduction in myocardial infarction area,down-regulated expression of cGAS,STING,and NF-κB p-p65 proteins,and markedly decreased levels of IL-1β and TNF-α compared with CME group(P<0.05).CONCLUSION:STDP pre-treatment ameliorated myocardial injury,cardiac dysfunction and myocardial infarct size induced by CME.The underlying mechenism may involve the suppression of the cGAS-STING signaling pathway,thereby attenuating myocardial inflamma-tion after CME.

Objective:To investigate the diagnostic value of metagenomic next-generation sequencing (mNGS) for pyogenic spinal infections.Methods:A total of 255 patients diagnosed with pyogenic spinal infections were enrolled between September 2022 and September 2024 at Qingdao University Affiliated Hospital, Fuzhou Second General Hospital, First Affiliated Hospital of Nanchang University, Shandong University Affiliated Public Health Clinical Center, and the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine. Among them, 155 were male and 100 were female, with an average age of 62.5±14.2 years (ranging from 13 to 90 years). All patients had samples of infected tissue and/or pus collected for microbial culture and mNGS testing. The number, types, and positive rates of pathogens detected by microbial culture and mNGS were compared. Using culture results as the gold standard, receiver operating characteristic (ROC) curve analysis was performed for mNGS testing and the combined method of mNGS and microbial culture, calculating the area under the curve (AUC) and 95% CI. Results:All 255 cases were clinically diagnosed as pyogenic spinal infections, with 194 cases providing microbiological evidence. The most common Gram-positive bacterium was Staphylococcus aureus, while the most common Gram-negative bacterium was Escherichia coli. A total of 33 pathogenic microorganisms were detected by mNGS, while microbial culture detected 18 pathogenic microorganisms. The positive rate of mNGS was 72.2% (184 out of 255), which was significantly higher than that of 30.2% (77 out of 255) for microbial culture, showing a significant difference (χ 2=90.150, P<0.001); the positive rate of mNGS combined with microbial culture was 76.1% (194 out of 255) with significant difference compared to mNGS alone (χ 2=8.100, P<0.001). Among 178 culture-negative samples, the detection rate of mNGS was 65.7% (117 out of 178); among 77 culture-positive samples, the detection rate of mNGS was 87.0% (67 out of 77), and 97.0% (65 out of 67) of the detected pathogens matched the culture results at the species level. The AUCs of the ROC curves for mNGS testing and the combination of mNGS with microbial culture were 0.606 [95% CI (0.534, 0.678)] and 0.671 [95% CI (0.606, 0.736)], respectively, with significant differences compared to microbial culture ( P=0.007; P=0.007). Conclusions:mNGS demonstrates superior performance over conventional culture in identifying pathogens in pyogenic spinal infections. Moreover, combining mNGS with culture further improves diagnostic yield, supporting its integration into clinical practice.

AIM:To investigate the protective effect of Shexiang-Tongxin dropping pills(STDP)against myo-cardial injury induced by coronary microembolization(CME)in rats,with a focus on the cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway.METHODS:Thirty-two Sprague-Dawley rats were randomly allocated into four groups using a random number table:sham group,CME group,STDP group,and RU.521 group,with 8 rats per group.A rat model of CME was established via the injection of embolic microspheres into the left ventricle.The rats in sham group received an equal volume of normal saline via left ventricular injection instead,those in STDP group were given STDP(40 mg/kg)by oral gavage once daily for 14 consecutive days before CME modeling,and those in RU.521 group were intraperitoneally injected with RU.521(5 mg/kg)once daily for 7 consecutive days before CME modeling.Echocardiography was performed to evaluate cardiac function 24 h after modeling.HE staining was used to observe pathological changes in myocardial tissue,and TTC staining was applied to detect myocardial infarction areas.Enzyme-linked immunosorbent assay(ELISA)was used to measure levels of interleukin(IL)-1β and tumor necrosis factor(TNF)-α.A commercial assay kit was employed to detect myocardial injury marker cardiac troponin I(cTnI).Western blot was performed to analyze the expression of cGAS-STING pathway-related proteins in cardiac tissues.RESULTS:Compared with sham group,the rats in CME group exhibited significantly impaired cardiac function and a marked increase in serum cTnI levels(P<0.05).In contrast,compared with CME group,the rats in both STDP group and RU.521 group demonstrated significant improvements in cardiac function and reductions in cTnI levels((P<0.05).Furthermore,HE staining and TTC staining revealed that the rats in CME group had loosely arranged myocardial fibers,swollen cardiomyo-cytes,and an increased myocardial infarction erea compared with sham group(P<0.05).Meanwhile,the expression lev-els of inflammatory factors IL-1β and TNF-α,as well as the relative expression of cGAS,STING and NF-κB p-p65 pro-teins were significantly increased(P<0.05).In comparison,the rats in STDP group and RU.521 group showed a signifi-cant reduction in myocardial infarction area,down-regulated expression of cGAS,STING,and NF-κB p-p65 proteins,and markedly decreased levels of IL-1β and TNF-α compared with CME group(P<0.05).CONCLUSION:STDP pre-treatment ameliorated myocardial injury,cardiac dysfunction and myocardial infarct size induced by CME.The underlying mechenism may involve the suppression of the cGAS-STING signaling pathway,thereby attenuating myocardial inflamma-tion after CME.

Objectives:To investigate the genetic etiology of six adult patients with Dilated cardiomyopathy (DCM), and analyze the structure of the identified variants, for providing reference for the diagnosis of DCM.Methods:Six adult patients with DCM (patients 1-6) admitted to the Department of Cardiology of Zhumadian Central Hospital from January 2023 to December 2023 were recruited. Clinical data of the patients were retrospectively collected. And 3 mL of peripheral blood was collected from each patients. Pathogenic variants patients were detected by whole exome sequencing (WES), and candidate variants were verified by Sanger sequencing. The possible functional significance of the identified missense variants was evaluated using software including SIFT, PolyPhen-2 and Mutation Taster. Specific regions of the MYBPC protein encoded by the MYBPC3 gene from different species were aligned using Mutation Taster. The wild-type and mutant MYBPC proteins were constructed using homologous modeling software MODELLER v10.4 and three-dimensional structures were visualized using PyMOL software. The molecular interaction between MYBPC-C5 domain and myosin with or without the mutation was further analyzed using ZDOCK module in Discovery Studio 2019 software. Pathogenicity ratings for the detected variant sites were performed in accordance with the Standards and Guidelines for the Interpretation of Sequence variants by the American College of Medical Genetics and Genomics (ACMG) (hereafter referred to as the ACMG Guidelines). This study was reviewed and approved by the Ethics Committee of Zhumadian Central Hospital (Approval No. 2022092007). Results:The six DCM patients had typical symptoms of heart failure, and echocardiography showed whole-heart dilation and decreased ventricular wall motion. Left ventricular end-diastolic dimension (LVEDD) was 57-74 mm, left ventricular ejection fraction (LVEF) was 35%-43%, and left ventricular fractional shortening (LVFS) was 17%-28%. Variation in DCM related genes, the c. 98473A>T(p.Lys32825*) variation of the TTN gene and the c.1976T>C(p.Ile659Thr) variation of the MYBPC3 gene, were identified in two patients with DCM. Multiple software predicted that both mutations were deleterious. MYBPC3-Ile659Thr mutation affected the highly conserved residue within the C5 domain of MYBPC. Three-dimensional structural analysis of homologous modeling revealed the alterations in amino acid properties and interactions with surrounding amino acids caused by the MYBPC3-Ile659Thr mutation. Further molecular docking analysis showed that the Ile659Thr mutation altered both the hydrogen bond and salt-bridge interactions between the MYBPC-C5 domain and the ligand myosin. Conclusions:Two mutations associated with DCM were identified in this study. The abnormal conformation of the mutant protein further affected its interaction with the ligand myosin, resulting in the phenotype of DCM.