Assessment of high sensitivity C-reactive protein and coronary plaque characteristics by computed tomography in patients with and without diabetes mellitus.

BACKGROUND: To evaluate the coronary plaque characteristics of coronary arteries using computed tomography angiography (CTA) in order to assess the risk of coronary artery disease and the relevance of high sensitivity C reactive protein (hs-CRP) in patients with Diabetes Mellitus (DM). METHODS: The clinical data of 400 DM patients and 400 non-DM patients from January 2017 to December 2019 were collected, including the results of coronaryCTA. The plasma hs-CRP level of the two groups were divided into three groups: CRP ≤ 1, 1 < CRP ≤ 2, CRP > 2. The correlation of the degree of stenosis, the number of plaques, the nature of plaques and hs-CRP value between the two groups was evaluated. RESULTS: Compared with non-DM patients, the incidence of coronary artery plaques and lumen stenosis in DM patients was more higher than that in non-DM patients. DM patients were more likely to have more diseased vessels, especially diffuse vascular disease (12.00% vs 1.75%; P < 0.001). Subjects with high hs-CRP levels were more likely to have any plaque compared with individuals showing normal hs-CRP levels (p<0.01). There was no statistical significance in non calcified plaque with high level of hs-CRP, but the occurrence of plaque types in DM group was statistically significant compared with other hs-CRP levels in non DM group. Subjects with high hs-CRP were observed to be at increased risk for the presence of calcified plaque and severe narrowing in the unadjusted values. CONCLUSIONS: Coronary CTA combined with hs-CRP can accurately detect the characteristics of coronary artery stenosis and plaque in DM patients, which has an important clinical value in the risk assessment of coronary heart disease in DM patients.

CT pulmonary angiogram for assessing the treatment outcome of acute pulmonary embolism.

OBJECTIVE: To discuss the value of CT pulmonary angiogram (CTPA) for assessing the treatment outcome of acute pulmonary embolism (APE). MATERIALS AND METHODS: CT pulmonary angiogram data and other clinical data were collected for 28 cases diagnosed as APE and analyzed retrospectively. The number and positions of emboli in the pulmonary artery, pulmonary artery obstruction index, right ventricular/left ventricular diameter ratio, main pulmonary artery/ascending aorta diameter ratio and blood oxygen saturation, and pulmonary arterial pressure were compared before and after treatment. RESULTS: Of 28 cases, emboli in the pulmonary artery completely or partially disappeared in 16 and 12 cases, respectively. CPTA indicated that the pulmonary arterial pressure decreased dramatically and the blood oxygen saturation increased after treatment in 26 cases. There were significant differences in the number and positions of pulmonary emboli and in pulmonary artery obstruction index before and after treatment in 28 cases (P < .05). However, no significant differences were found in the right ventricular/left ventricular diameter ratio or main pulmonary artery/ascending aorta diameter ratio (P > .05). CONCLUSION: CT pulmonary angiogram proved reliable for assessing the treatment efficacy of APE, providing more clinical information on the patients' status.

MicroRNA-22 Promoted Osteogenic Differentiation of Human Periodontal Ligament Stem Cells by Targeting HDAC6.

Stem cells transplantation is a promising therapy strategy for accelerating periodontal regeneration and reconstruction. Genetic modification could induce stem cells directional differentiation to facilitate recovery of physiological functions. In this study, we investigated the role and mechanism of miR-22 on human periodontal ligament stem cells (PDLSCs). First, a cellular model of osteogenic differentiation was first established by osteogenic inductive cocktail. Real-time PCR determined that expression of miR-22 was significantly increased during PDLSCs osteogenic differentiation. Alizirin red staining showed that overexpression of miR-22 in PDLSCs induced better mineralized nodule formation. Real-time PCR and Western blot further confirmed up-regulation of osteogenic genes Runx2 and OPN in miR-22-overexpressing PDLSCs. Conversely, inhibition of miR-22 delayed the process of PDLSCs osteogenic differentiation. Furthermore, Histone deacetylase 6 (HDAC6) was identified as a target gene of miR-22. Overexpression of miR-22 not only reduced the luciferase activity of the reporter containing the 3' untranslated region of HDAC6 mRNA, but also suppressed the endogenous protein expression of HDAC6. Rescue experiment showed that the promotion role of miR-22 in osteogenic differentiation could be relieved by overexpression of HDAC6. Meanwhile, overexpression of HDAC6 alone could also delay the osteogenic differentiation process. The results demonstrated that miR-22 promoted PDLSCs osteogenic differentiation by inhibiting HDAC6 expression, suggesting that miR-22 might be developed as a target of genetic modified stem cells therapy for periodontal diseases. J. Cell. Biochem. 118: 1653-1658, 2017. © 2017 Wiley Periodicals, Inc.

Differential expression profile of long non-coding RNA in cardiomyocytes autophagy induced by angiotensin II.

Autophagy is a ubiquitous intracellular process for cellular homeostasis maintenance by recycling damaged protein and organelles. Dysregulation of cardiomyocytes autophagic activity is implicated in various heart diseases. Recent studies had demonstrated that long non-coding RNAs (lncRNAs) played crucial roles on modulation of autophagic activity. In this study, we first established an angiotensin II-induced autophagy model on neonatal rat cardiomyocytes. Western blot assay confirmed that the expression of Beclin 1 and the conversion of soluble LC3-I to lipid bound LC3-II were significantly increased at 12 h after angiotensin II stimulation, but the cardiomyocytes surface area and hypertrophic markers expression had no significant change. Then microarray analysis and real-time PCR were applied to detect differentially expressed lncRNAs during cardiomyocytes autophagy. A total of 1,249 lncRNAs were determined as differentially expressed, including 700 upregulated lncRNAs and 549 downregulated lncRNAs. LncRNAs subgroup analysis showed there were 43 transcribed ultra-conserved noncoding RNAs (T-UCRs) differentially expressed in cardiomyocytes autophagy, of which 26 T-UCRs were upregulated and 17 T-UCRs were downregulated. Bioinformatics analysis further showed that 94 differentially expressed lncRNAs contained potential binding sites of miR-22, a pro-hypertrophic and pro-autophagic microRNA. Therefore, these differentially expressed lncRNAs might play critical roles in cardiomyocytes autophagy. This finding would provide an experimental basis for future investigation on ischemic heart disease.

Multislice spiral CT angiography for evaluation of acute aortic syndrome.

OBJECTIVE: To discuss the diagnostic value of multislice CT angiography (MSCTA) in acute aortic syndrome (AAS). MATERIALS AND METHODS: The clinical and imaging data of 36 cases diagnosed as AAS by MSCTA were collected. The manifestations of the MSCTA images were reviewed retrospectively, and the average x-ray dose was calculated. RESULTS: Among 36 AAS cases, 16 cases had aortic dissection (AD), 8 cases had penetrating atherosclerotic ulcer (PAU), 7 cases had intramural hematoma (IMH), and 5 cases had unstable thoracic aneurysm (UTA). Of 16 cases with AD, type A and type B accounted for 43.7% (7/16) and 56.3% (9/16), respectively. Of 7 cases with IMH, type A and type B accounted for 42.9% (3/7) and 57.1% (4/7), respectively. CONCLUSION: In spite of the x-ray radiation, MSCTA proves to be a rapid and noninvasive imaging technique for the diagnosis of AAS.

ECG-gated pulmonary artery CTA for evaluation of right ventricular function in patients with acute pulmonary embolism.

OBJECTIVE: To evaluate right ventricular function in patients with acute pulmonary embolism (APE) using electrocardiogram-gated CTA and to discuss the clinical value of pulmonary artery CTA PATIENTS AND METHODS: Based on death risk evaluation, 86 APE patients were divided into high-risk group (n=46) and non-high-risk group (n=40). The CT pulmonary embolism (PE) index and parameters of right ventricular function were analyzed from the CTPA images and compared between the two groups. Potential correlation between the two was also discussed. RESULT: CT PE index (median 24.69%) of the high-risk group was obviously higher than that of the non-high-risk group (median 8.58%) (P<.05). Except the diameter of superior vena cava, all other parameters of right ventricular function were significantly different between the two groups (P<.05). CT PE index was correlated with the parameters of right ventricular function. CONCLUSION: ECG-gated pulmonary artery CTA is suitable for assessing the severity of APE and right ventricular function.

Dynamic autophagic activity affected the development of thoracic aortic dissection by regulating functional properties of smooth muscle cells.

The aortic medial degeneration is the key histopathologic feature of Thoracic aortic dissection (TAD). The aim of this study was to identify the change of autophagic activity in the aortic wall during TAD development, and to explore the roles of autophagy on regulating functional properties of smooth muscle cells (SMCs). Firstly, compared with control group (n = 11), the increased expression of autophagic markers Beclin1 and LC3 was detected in the aortic wall from TAD group (n = 23) by immunochemistry and western blot. We found that more autophagic vacuoles were present in the aortic wall of TAD patients using Transmission electron microscopy. Next, autophagic activity was examined in AD mice model established by ß-aminopropionitrile fumarate (BAPN) and angiotensin II. Immunochemistry proved that autophagic activity was dynamically changed during AD development. Beclin1 and LC3 were detected up-regulated in the aortic wall in the second week after BAPN feeding, earlier than the fragmentation or loss of elastic fibers. When AD occurred in the 4th week, the expression of Beclin1 and LC3 began to decrease, but still higher than the control. Furthermore, autophagy was found to inhibit starvation-induced apoptosis of SMCs. Meanwhile, blockage of autophagy could suppress PDGF-induced phenotypic switch of SMCs. Taken together, autophagic activity was dynamically changed in the aortic wall during TAD development. The abnormal autophagy could regulate the functional properties of aortic SMCs, which might be the potential pathogenesis of TAD.

Evaluation of image quality in carotid and cerebrovascular disease: a comparative study between subtraction and routine computed tomography angiography.

OBJECTIVE: Few data exist comparing the image quality and diagnostic accuracy of subtraction computed tomography (CT) angiography (SCTA) in carotid and cerebrovascular arteries with routine CT angiography (RCTA). PATIENTS AND METHODS: In this study, 56 patients underwent 128-row CT angiography of these vessels with review by two radiologists using routine, nonsubtracted, and SCTA protocols. Comparisons were made using a 4-point subjective rating scale in all patients. Eighteen patients were examined with both SCTA and invasive digital subtraction angiography (DSA). The accuracy of SCTA and routine CTA reformations was assessed and compared by both patient-based and vessel-based analyses of intracranial aneurysms and intracranial and extracranial arterial stenotic lesions using DSA results as the reference standard. RESULTS: Diagnostic accuracy in the adjacent skull base portion of the internal carotid artery (ICA) and reading time for cerebral aneurysms and vessel stenoses were obviously improved with SCTA protocol, but the accuracy in vertebro-basilar arteries was no different. The diagnostic accuracy in general was slightly increased compared with routine CTA. CONCLUSION: Review of SCTA images is an effective means to remove bone close to vessels as seen on routine CTA and has good image quality and diagnostic accuracy. SCTA is superior to routine CTA in the visualization and diagnostic accuracy of adjacent skull base part of the ICA and decreases reading time for carotid and cerebrovascular arterial imaging.

Combining Coronary with Carotid and Cerebrovascular Angiography Using Prospective ECG Gating and Iterative Reconstruction with 256-slice CT.

OBJECTIVE: To investigate the image quality and radiation dose of combined coronary and carotid/cerebrovascular angiography with ECG gating and iterative reconstruction using 256-slice CT compared with the findings with the two examinations performed separately. PATIENTS AND METHODS: One hundred sixty-five consecutive patients underwent a single-injection single-pass combination of coronary and carotid/cerebrovascular CT angiography (group A), coronary CT angiography alone (group B), or carotid/cerebrovascular CT angiography alone (group C). We assessed the image quality of the combined and separate examinations and calculated the respective effective radiation doses. We evaluated the differences in the proportions of image quality grade between the combination and single-examination groups. Diagnostic performance of the combined scanning for detecting significant vascular stenosis has been compared with reference digital subtraction angiography (DSA) in the patient subgroup of group A. RESULTS: There was no significant difference in age, body mass index (BMI), or gender distribution among the 3 groups (all P > 0.05). But there was significant difference in scan length, DLP, and effective dose among the 3 groups (all P < 0.05). There were no significant differences in the effective radiation dose of coronary scanning between groups A and B (P > 0.05), while the effective radiation dose of carotid/cerebrovascular scanning in group A was significantly lower than that in group C (P < 0.05), and the total effective radiation dose in group A were relatively low (2.21 ± 1.38 mSv). The differences of the proportion of carotid/cerebrovascular image quality grades between groups A and C were not significant (P > 0.05). In a subgroup of group A of 30 patients with DSA, combined computed tomographic angiography successfully detected 56 coronary stenosis on per-segment basis, and 62 stenosis on carotid and cerebral artery. The sensitivity, specificity, positive and negative predictive value (NPV) of coronary stenosis were 91.80%, 95.60%, 87.50% and 97.21%, respectively. The sensitivity, specificity, positive and NPV of carotid/cerebrovascular stenosis were 93.55%, 94.68%, 92.06% and 95.70%, respectively. CONCLUSION: Combination of coronary and carotid/cerebrovascular angiography with 256-slice CT scanner with prospective ECG gating and iterative reconstruction produces diagnostic-quality images of the coronary, carotid, and cerebrovascular systems in a single examination, using less contrast medium and a lower radiation dose than when the two examinations are performed separately. This novel technique has high accuracy in detecting significant stenosis in one image setting.

Uracils at nucleotide position 9-11 are required for the rapid turnover of miR-29 family.

MicroRNAs are endogenous small RNA molecules that regulate gene expression. Although the biogenesis of microRNAs and their regulation have been thoroughly elucidated, the degradation of microRNAs has not been fully understood. Here by using the pulse-chase approach, we performed the direct measurement of microRNA lifespan. Five representative microRNAs demonstrated a general feature of relatively long lifespan. However, the decay dynamic varies considerably between these individual microRNAs. Mutation analysis of miR-29b sequence revealed that uracils at nucleotide position 9-11 are required for its rapid decay, in that both specific nucleotides and their position are critical. The effect of uracil-rich element on miR-29b decay dynamic occurs in duplex but not in single strand RNA. Moreover, analysis of published data on microRNA expression profile during development reveals that a substantial subset of microRNAs with the uracil-rich sequence tends to be down-regulated compared to those without the sequence. Among them, Northern blotting shows that miR-29c and fruit fly bantam possess a relatively rapid turnover rate. The effect of uracil-rich sequence on microRNA turnover depends on the sequence context. The present work indicates that microRNAs contain sequence information in the middle region besides the sequence element at both ends.

Attenuation of microRNA-22 derepressed PTEN to effectively protect rat cardiomyocytes from hypertrophy.

Cardiac hypertrophy, which is characterized by the enlargement of cell size, reactivation of fetal genes, remains one of the most important triggers to heart failure. Increasing evidence shows that microRNA (miRNA) is extensively involved in the pathogenesis of cardiac hypertrophy. But the effects of miRNAs on cardiomyocyte hypertrophy have not been completely solved yet. Here, we showed that a collection of miRNAs was aberrantly expressed in hypertrophic cardiomyocytes induced by phenylephrine (PE) or angiotensin II (Ang II). Among them, miR-22 was the most strikingly up-regulated miRNA. To investigate the role of miR-22 in hypertrophy, both over-expression and knock-down assays were performed on cardiomyocytes. The results showed that up-regulation of miR-22 significantly increased the cell size and markedly influenced the expression of hypertrophic markers, including induction of nppa and reduction of myh6. In contrast, reduction of miR-22 level attenuated either PE- or Ang II-induced hypertrophic reaction. Furthermore, several genes, including PTEN, were identified as potential targets of miR-22 by bioinformatic algorithms. Using luciferase analysis, miR-22 could significantly suppress the luciferase activity of reporter fused with 3' untranslated region of PTEN mRNA. Furthermore, up-regulation of miR-22 could suppress the protein level of PTEN and reduction of miR-22 level markedly increased the protein level of PTEN in cardiomyocytes by Western blot analysis, suggesting that the contribution of miR-22 to cardiomyocyte hypertrophy may be partially through targeting PTEN. Taken together, miRNAs were dynamically regulated in cardiomyocyte hypertrophy and attenuation of miR-22 in rat cardiomyocytes efficiently protected from hypertrophic effects through derepressing PTEN.

Attenuation of microRNA-1 derepresses the cytoskeleton regulatory protein twinfilin-1 to provoke cardiac hypertrophy.

MicroRNAs are involved in several aspects of cardiac hypertrophy, including cardiac growth, conduction, and fibrosis. However, their effects on the regulation of the cardiomyocyte cytoskeleton in this pathological process are not known. Here, with microRNA microarray and small RNA library sequencing, we show that microRNA-1 (miR-1) is the most abundant microRNA in the human heart. By applying bioinformatic target prediction, a cytoskeleton regulatory protein twinfilin-1 was identified as a potential target of miR-1. Overexpression of miR-1 not only reduced the luciferase activity of the reporter containing the 3' untranslated region of twinfilin-1 mRNA, but also suppressed the endogenous protein expression of twinfilin-1, indicating that twinfilin-1 is a direct target of miR-1. miR-1 was substantially downregulated in the rat hypertrophic left ventricle and phenylephrine-induced hypertrophic cardiomyocytes, and accordingly, the protein level of twinfilin-1 was increased. Furthermore, overexpression of miR-1 in hypertrophic cardiomyocytes reduced the cell size and attenuated the expression of hypertrophic markers, whereas silencing of miR-1 in cardiomyocytes resulted in the hypertrophic phenotype. In accordance, twinfilin-1 overexpression promoted cardiomyocyte hypertrophy. Taken together, our results demonstrate that the cytoskeleton regulatory protein twinfilin-1 is a novel target of miR-1, and that reduction of miR-1 by hypertrophic stimuli induces the upregulation of twinfilin-1, which in turn evokes hypertrophy through the regulation of cardiac cytoskeleton.

The antioxidative defense system is involved in the delayed senescence in a wheat mutant tasg1.

Wheat, which is the most important food crop worldwide, is a cereal that presents considerable potential for increased yield. A new wheat (Triticum aestivum L.) mutant tasg1 with delayed leaf senescence was constructed using ethyl methane sulfonate as a mutagen. Natural senescence in tasg1 was distinctly delayed in the field, as indicated by the slower progression of chlorophyll degradation, net photosynthetic rate than its wild type. Further, the malondialdehyde and the hydrogen peroxide content was lower and antioxidative enzyme activity higher in tasg1 than those in its wild type during both natural senescence and methyl viologen-induced oxidative stress. The results suggest that tasg1 is a functional stay-green wheat mutant with the Type B (in which senescence initiates on schedule, but progresses at a rate lower than that in the respective WTs) or Type A (in which senescence initiates late but proceeds at a normal rate) and B combination and that the competence of the antioxidant defense system is one of the most important mechanisms underlying the expression of the stay-green phenotype.

Increased gibberellin contents contribute to accelerated growth and development of transgenic tobacco overexpressing a wheat ubiquitin gene.

KEY MESSAGE: Overexpressing TaUb2 promoted stem growth and resulted in early flowering in transgenic tobacco plants. Ubiquitin are involved in the production, metabolism and proper function of gibberellin. The ubiquitin-26S proteasome system (UPS), in which ubiquitin (Ub) functions as a marker, is a post-translational regulatory system that plays a prominent role in various biological processes. To investigate the impact of different Ub levels on plant growth and development, transgenic tobacco (Nicotiana tabacum L.) plants were engineered to express an Ub gene (TaUb2) from wheat (Triticum aestivum L.) under the control of cauliflower mosaic virus 35S promoter. Transgenic tobacco plants overexpressing TaUb2 demonstrated an accelerated growth rate at early stage and an early flowering phenotype in development. The preceding expression of MADS-box genes also corresponded to the accelerated developmental phenotypes of the transgenic tobacco plants compared to that of wild-type (WT). Total gibberellin (GA) and active GA contents in transgenic tobacco plants were higher than those in WT at the corresponding developmental stages, and some GA metabolism genes were upregulated. Treatment with GA(3) conferred a similarly accelerated grown rate in WT plants to that of transgenic tobacco plants, while growth was inhibited when transgenic tobacco plants were treated with a GA biosynthesis inhibitor. Thus, the results suggest that Ub are involved in the production, metabolism and proper function of GA, which is important in the regulation of plant growth and development.

Vascular smooth muscle cell proliferation is influenced by let-7d microRNA and its interaction with KRAS.

BACKGROUND: Several microRNAs (miRNAs) have been reported to regulate cardiovascular biological and pathological processes through inhibiting the translation of certain RNA transcripts. However, little is known about the association between miRNAs and vascular smooth muscle cell (VSMC) proliferation. The aim was to investigate the role of miRNAs in VSMC growth and the potential mechanism. METHODS AND RESULTS: Primary VSMCs were isolated from the medial layer of the thoracic aorta obtained from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). miRNA microarrays were used to analyze the difference in miRNA expression between VSMCs of SHR and WKY rats and were validated using TaqMan real-time PCR. Of the potentially related genes under the influence of let-7d identified through literature search, KRAS was verified by western blot and functionally analyzed using miRNA mimics transfection and analysis of transfectants by cell enumeration was made using CCK-8 and flow cytometric analysis of cell cycle progression. let-7d-transfected VSMCs from SHR, WKY and human coronary arteries expressed significantly lower amounts of KRAS protein, displayed reduced cell growth and led to a greater number of cells in the G1 phase than the G2/M phases of the cell cycle. CONCLUSIONS: let-7d was significantly downregulated in VSMCs as an important regulator of cell proliferation. RAS might be involved in the proliferation regulation by let-7d.

Circulating microRNA: a novel potential biomarker for early diagnosis of acute myocardial infarction in humans.

AIMS: microRNA (miRNA) is reported to be present in the blood of humans and has been increasingly suggested as a biomarker for diseases. We aim to determine the potential of cardiac-specific miRNAs in circulation to serve as biomarkers for acute myocardial infarction (AMI). METHODS AND RESULTS: By verifying their tissue expression patterns with real-time polymerase chain reaction (PCR) analysis, muscle-enriched miRNAs (miR-1, miR-133a, and miR-499) and cardiac-specific miR-208a were selected as candidates for this study. With miRNA microarray and real-time PCR analyses, miR-1, miR-133a, and miR-499 were present with very low abundance, and miR-208a was absent in the plasma from healthy people. In the AMI rats, the plasma levels of these miRNAs were significantly increased. Especially, miR-208a in plasma was undetected at 0 h, but was significantly increased to a detectable level as early as 1 h after coronary artery occlusion. Further evaluation of the miRNA levels in plasma from AMI patients (n = 33) demonstrated that all four miRNA levels were substantially higher than those from healthy people (n = 30, P < 0.01), patients with non-AMI coronary heart disease (n = 16, P < 0.01), or patients with other cardiovascular diseases (n = 17, P < 0.01). Notably, miR-208a remained undetectable in non-AMI patients, but was easily detected in 90.9% AMI patients and in 100% AMI patients within 4 h of the onset of symptoms. By receiver operating characteristic curve analysis, among the four miRNAs investigated, miR-208a revealed the higher sensitivity and specificity for diagnosing AMI. CONCLUSION: Elevated cardiac-specific miR-208a in plasma may be a novel biomarker for early detection of myocardial injury in humans.

MicroRNAs are dynamically regulated in hypertrophic hearts, and miR-199a is essential for the maintenance of cell size in cardiomyocytes.

Cardiac hypertrophy, which is characterized by an increase in cell size and reactivation of fetal genes, occurs as an adaptive response to diverse forms of stress and often results in heart failure and sudden death. Growing evidence indicates that microRNAs (miRNAs) are involved in cardiac hypertrophy, but the function of these miRNAs remains elusive. Here, using real time PCR analysis, we showed that several miRNAs were dynamically regulated in the rat hypertrophic hearts and miR-199a was up-regulated by 10-fold in hypertrophic hearts after abdominal aorta constriction for 12 weeks. With tissue profiling analysis, we showed that miR-199a was predominantly expressed in cardiomyocytes, but was also faintly detected in cardiac fibroblasts. To investigate whether miR-199a was involved in cardiac hypertrophy, both over-expression and knockdown of miR-199a were performed in cultured cardiomyocytes. Over-expression of miR-199a in cardiomyocytes increased the cell size as measured by cell surface area, and also reduced the mRNA expression level of alpha-myosin heavy chain. In accordance, knockdown of endogenous miR-199a in cardiomyocytes reduced the cell size. Down-regulation of miR-199a also attenuated the phenylephrine-induced increase of cell size. Furthermore, bioinformatic algorithms were used to predict the potential targets of miR-199a in cardiac hypertrophy, and hypoxia-inducible factor 1 alpha was confirmed by the luciferase reporter assay to be a potential target of miR-199a. Taken together, our results demonstrated that miR-199a, which was predominantly expressed in cardiomyocytes, was essential for the maintenance of cell size of cardiomyocytes and might play a role in the regulation of cardiac hypertrophy.

Involvement of Oct4 in the pathogenesis of thoracic aortic dissection via inducing the dedifferentiated phenotype of human aortic smooth muscle cells by directly upregulating KLF5.

OBJECTIVE: To investigate the expression of Oct4 in human thoracic aortic dissection (TAD) and the regulation mechanisms of Oct4 on phenotype transition of human aortic smooth muscle cells (HASMCs). METHODS: Aortic samples from TAD patients (n = 12) and organ donors (n = 6) were collected. qRT-PCR, western blot, and immunohistochemistry were performed to identify Oct4 expression in aortic media. Immunofluorescence was performed to analyze Oct4 expression in primary HASMCs. Oct4A and Oct4B isoforms were detected. Gain-of-function experiments were performed to determine the effects of Oct4 on HASMC phenotype transition. Chromatin immunoprecipitation, luciferase assay, and rescue experiments were performed to analyze mechanisms of Oct4 on HASMC phenotype transition. RESULTS: Oct4 expression levels, especially the Oct4A isoform, were significantly higher in TAD patients compared with normal controls. Notably, Oct4 presented a strong and strict nuclear localization in primary HASMCs of TAD patients but a mild and diffuse distribution in both cytoplasm and nucleus in the control group. Overexpression of Oct4 induced dedifferentiation of HASMCs characterized by decreased contractile proteins and elevated migration capability. Krüppel-like factor 5 (KLF5) was found to be a directly regulated target gene of Oct4 in HASMCs. Furthermore, downregulation of KLF5 significantly alleviated the effects of Oct4 on phenotype transition of HASMCs. CONCLUSIONS: Oct4 expression was significantly upregulated in aortic tissues and primary HASMCs of TAD patients. The increased Oct4 induced phenotype transition of HASMCs from the contractile type to the synthetic type by directly upregulating KLF5.

Inhibition of heat shock protein 90 improves pulmonary arteriole remodeling in pulmonary arterial hypertension.

While the molecular chaperone heat shock protein 90 (HSP90) is involved in a multitude of physiological and pathological processes, its role relating to pulmonary arterial hypertension (PAH) remains unclear. In the present study, we investigated the effect in which HSP90 improves pulmonary arteriole remodeling, and explored the therapeutic utility of targeting HSP90 as therapeutic drug for PAH. By Elisa and immunohistochemistry, HSP90 was found to be increased in both plasma and membrane walls of pulmonary arterioles from PAH patients. Moreover, plasma HSP90 levels positively correlated with mean pulmonary arterial pressure and C-reactive protein. In a monocrotaline-induced rat model of PH, we found that 17-AAG, a HSP90-inhibitor, alleviated the progress of PH, demonstrated by lower pulmonary arterial pressure and absence of right ventricular hypertrophy. Immunohistochemical staining demonstrated that 17-AAG improved pulmonary arteriole remodeling on the basis of reduced wall thickness and wall area. The inflammatory response attributed to PH could be attenuated by 17-AAG through reduction of NF-κB signaling. Moreover, 17-AAG was found to suppress PDGF-stimulated proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) through induction of cell cycle arrest in the G1 phase. In conclusion, HSP90 inhibitor 17-AAG could improve pulmonary arteriole remodeling via inhibiting the excessive proliferation of PASMCs, and inhibition of HSP90 may represent a therapeutic avenue for the treatment of PAH.

Brahma-related gene 1 inhibits proliferation and migration of human aortic smooth muscle cells by directly up-regulating Ras-related associated with diabetes in the pathophysiologic processes of aortic dissection.

OBJECTIVE: To elucidate the mechanisms of Brahma-related gene 1 (Brg1) involvement in the pathophysiologic processes of aortic dissection. METHODS: Seventeen dissecting, 4 dilated, and 10 healthy human aorta samples were collected. Expression of Brg1 in the medium of aorta was evaluated by quantitative real-time polymerase chain reaction, Western blot, and immunohistochemical staining, respectively. The regulation effect of Brg1 on proliferation and migration of human aortic smooth muscle cells (HASMCs) was analyzed in 3 ways: using cell counting, a migration chamber, and a wound scratch assay. A polymerase chain reaction array was used for screening potential target genes of Brg1. A chromatin immunoprecipitation assay was adopted for direct deoxyribonucleic acid-protein binding detection. RESULTS: Expression levels of Brg1 were increased in aortic dissection and aortic dilation patients. In vitro results indicated that overexpression of Brg1 inhibited proliferation and migration of HASMCs. The candidate proliferation- and migration-related Brg1 target gene found was Ras-related associated with diabetes (RRAD), expression levels of which were enhanced in dissecting aortic specimens. The direct regulation effect of Brg1 on RRAD was verified by chromatin immunoprecipitation assay results. Furthermore, down-regulating RRAD significantly alleviated the suppression effects of Brg1 on proliferation and migration of HASMCs. CONCLUSIONS: Our study illustrated that Brg1 inhibited the proliferation and migration capacity of HASMCs, via the mechanism of direct up-regulation of RRAD, thus playing an important role in the pathophysiologic processes of aortic dissection.