Hypoxia-associated genes predicting future risk of myocardial infarction: a GEO database-based study.

Background: Patients with unstable angina (UA) are prone to myocardial infarction (MI) after an attack, yet the altered molecular expression profile therein remains unclear. The current work aims to identify the characteristic hypoxia-related genes associated with UA/MI and to develop a predictive model of hypoxia-related genes for the progression of UA to MI. Methods and results: Gene expression profiles were obtained from the GEO database. Then, differential expression analysis and the WGCNA method were performed to select characteristic genes related to hypoxia. Subsequently, all 10 hypoxia-related genes were screened using the Lasso regression model and a classification model was established. The area under the ROC curve of 1 shows its excellent classification performance and is confirmed on the validation set. In parallel, we construct a nomogram based on these genes, showing the risk of MI in patients with UA. Patients with UA and MI had their immunological status determined using CIBERSORT. These 10 genes were primarily linked to B cells and some inflammatory cells, according to correlation analysis. Conclusion: Overall, GWAS identified that the CSTF2F UA/MI risk gene promotes atherosclerosis, which provides the basis for the design of innovative cardiovascular drugs by targeting CSTF2F.

Therapeutic Hypothermia Inhibits Hypoxia-Induced Cardiomyocyte Apoptosis Via the MiR-483-3p/Cdk9 Axis.

Background Therapeutic hypothermia has a beneficial effect on cardiac function after acute myocardial infarction, but the exact mechanism is still unclear. Recent research has suggested that microRNAs participate in acute myocardial infarction to regulate cardiomyocyte survival. This study aimed to explore the ability of hypothermia-regulated microRNA-483-3p (miR-483-3p) to inhibit hypoxia-induced myocardial infarction. Methods and Results Primary cardiomyocytes were cultured under hypoxia at 32 °C to mimic therapeutic hypothermia, and the differentially expressed microRNAs were determined by RNA sequencing. Therapeutic hypothermia recovered hypoxia-induced increases in apoptosis, decreases in ATP levels, and decreases in miR-483-3p expression. Overexpression of miR-483-3p exhibited effects similar to those of therapeutic hypothermia on hypoxia in the treatment of cardiomyocytes to associate with maintaining the mitochondrial membrane potential, and cyclin-dependent kinase 9 (Cdk9) was identified as a target gene with downregulated expression by miR-483-3p. Knockdown of Cdk9 also promoted cardiac survival, ATP production, and mitochondrial membrane potential stability under hypoxia. In vivo, the expression of miR-483-3p and Cdk9 was tested in the cardiac tissue of the mice with acute myocardial infarction, and the expression of miR-483-3p decreased and Cdk9 increased in the region of myocardial infarction. However, miR-483-3p was overexpressed with lentivirus, which suppressed apoptosis, infarct size (miR-483-3p, 22.00±4.04% versus negative control, 28.57±5.44%, P<0.05), and Cdk9 expression to improve cardiac contractility. Conclusions MiR-483-3p antagonizes hypoxia, leading to cardiomyocyte injury by targeting Cdk9, which is a new mechanism of therapeutic hypothermia.

A systematic review and meta-analysis of the association between sarcopenia and myocardial infarction.

BACKGROUND: Systematic review and meta-analysis of the association between sarcopenia and the development of myocardial infarction. METHODS: PubMed, Cochrane Library, and Embase were searched for studies on the association between sarcopenia and myocardial infarction from their inception until November 26, 2022. The fixed-effects model was used to calculate the combined risk ratio (RR) of sarcopenia in patients with myocardial infarction. Sensitivity analysis was used to test the robust of the combined result, and funnel plot were used to test publication bias. RESULTS: Five studies were included finally. There was no significant association between sarcopenia and risk of developing myocardial infarction [RR = 1.01; 95% CI = 0.94, 1.08; P = 0.317]. The sensitivity analysis showed robust of the combined result. The funnel plot showed no significant publication bias. CONCLUSION: Limited evidence suggests no definitive association between sarcopenia and risk of myocardial infarction.

Chinese expert consensus on prevention and intervention for the elderly with malnutrition (2022).

Malnutrition is a state of altered body composition and body cell mass due to inadequate intake or utilization of energy or nutrients, leading to physical and mental dysfunction and impaired clinical outcomes. As one of the most common geriatric syndromes, malnutrition in the elderly is a significant risk factor for poor clinical outcomes, causing a massive burden on medical resources and society. The risk factors for malnutrition in the elderly are diverse and include demographics, chronic diseases, and psychosocial factors. Presently, recommendations for the prevention and intervention of malnutrition in the elderly are not clear or consistent in China. This consensus is based on the latest global evidence and multiregional clinical experience in China, which aims to standardize the prevention and intervention of malnutrition in the elderly in China and improve the efficacy of clinical practice and the prognosis of elderly patients.

Sarcopenia predicts adverse outcomes in an elderly population with coronary artery disease: a systematic review and meta-analysis.

BACKGROUND: The development of sarcopenia is attributed to normal aging and factors like type 2 diabetes, obesity, inactivity, reduced testosterone levels, and malnutrition, which are factors of poor prognosis in patients with coronary artery disease (CAD). This study aimed to perform a meta-analysis to assess whether preoperative sarcopenia can be used to predict the outcomes after cardiac surgery in elderly patients with CAD. METHODS: PubMed, Embase, the Cochrane library, and Web of Science were searched for available papers published up to December 2020. The primary outcome was major adverse cardiovascular outcomes (MACE). The secondary outcomes were mortality and heart failure (HF)-related hospitalization. The random-effects model was used. Hazard ratios (HRs) with 95% confidence intervals (95%CIs) were estimated. RESULTS: Ten studies were included, with 3707 patients followed for 6 months to 4.5 ± 2.3 years. The sarcopenia population had a higher rate of MACE compared to the non-sarcopenia population (HR = 2.27, 95%CI: 1.58-3.27, P < 0.001; I2 = 60.0%, Pheterogeneity = 0.02). The association between sarcopenia and MACE was significant when using the psoas muscle area index (PMI) to define sarcopenia (HR = 2.86, 95%CI: 1.84-4.46, P < 0.001; I2 = 0%, Pheterogeneity = 0.604). Sarcopenia was not associated with higher late mortality (HR = 2.15, 95%CI: 0.89-5.22, P = 0.090; I2 = 91.0%, Pheterogeneity < 0.001), all-cause mortality (HR = 1.35, 95%CI: 0.14-12.84, P = 0.792; I2 = 90.5%, Pheterogeneity = 0.001), and death, HF-related hospitalization (HR = 1.37, 95%CI: 0.59-3.16, P = 0.459; I2 = 62.0%, Pheterogeneity = 0.105). The sensitivity analysis revealed no outlying study in the analysis of the association between sarcopenia and MACE after coronary intervention. CONCLUSION: Sarcopenia is associated with poor MACE outcomes in patients with CAD. The results could help determine subpopulations of patients needing special monitoring after CAD surgery. The present study included several kinds of participants; although non-heterogeneity was found, interpretation should be cautious.

Generation of a human-derived induced pluripotent stem cell line (SIAISi012-A) from an 82-year-old healthy Chinese Han male.

As the global median population age increases, neurological diseases associated with aging pose significant challenges to human health. Appropriate modeling systems can be useful tools to better understand the mechanism of age-related neuronal degeneration diseases. Here, we successfully generated an iPSC-derived modeling system of an 82-year-old healthy man, this newly established line showed that all pluripotent markers were expressed, and the differentiation potential was confirmed by trilineage differentiation. STR profiling proved the cell line identity, and G-binding showed the normal karyotype.

Value of plasma homocysteine to predict stroke, cardiovascular diseases, and new-onset hypertension: A retrospective cohort study.

The influences of hyperhomocysteinemia on cardiovascular diseases (CVDs), stroke and new-onset hypertension are unclear. The aim of the study is to explore the associations of homocysteine levels with stroke, CVDs, and new-onset hypertension in Chinese individuals.This retrospective cohort study included outpatients and inpatients from the Department of Geriatrics at Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine from January to December 2000. They were divided based on their homocysteine (Hcy) levels in 2000: Q1 (<10 µmol/L), Q2 (10-15 µmol/L), and Q3 (>15 µmol/L) and according to whether they had hypertension at baseline. Information about stroke, mortality and major adverse cardiac events, and newly onset hypertension was gathered in December each year until 2017. The effects of Hcy levels on the risk for stroke and CVDs among all patients, and new-onset hypertension among patients without hypertension at baseline were evaluated.After adjustment for confounders, compared with the Q1 group (Hcy <10 µmol/L), when the Hcy increased to 10 to 15 µmol/L, the risks for stroke, CVDs, and new-onset hypertension significantly increased, and the hazard ratio and 95% confidence interval were 2.02 (1.35-3.05, P = .001), 2.22 (1.32-3.76, P = .003), and 7.20 (4.52-11.48, P < .001), respectively. Hcy improved the predictive capability of traditional risk factors for stroke. The optimal cut-off value of Hcy for predicting stroke was 13.4 µmol/L (sensitivity: 70.9%, specificity: 62.2%).Hcy 10 to 15 µmol/L is significantly associated with the risks for stroke, mortality and major adverse cardiac events, and hypertension. The best cut-off point of Hcy for predicting stroke is 13.4 µmol/L.

Sarcopenia is associated with hypertension in older adults: a systematic review and meta-analysis.

BACKGROUND: Sarcopenia, particularly low handgrip strength has been observed and correlated in association with hypertension among the older people. However, the results reported in different studies were inconsistent. In the current study, we conducted a systematic review and meta-analysis to reveal the significant association between sarcopenia, handgrip strength, and hypertension in older adults. METHODS: PubMed, MEDLINE, Cochrane Library, and EMBASE databases were searched from inception to 15 November 2019 to retrieve the original research studies that addressed the association between sarcopenia, handgrip strength, and hypertension. All the relevant data were retrieved, analyzed, and summarized. RESULTS: Twelve articles met the inclusion criteria and a total of 21,301 participants were included in the meta-analysis. Eight eligible studies have reported the odd ratios (ORs) of hypertension and sarcopenia, and the ORs ranged from 0.41 to 4.38. When pooled the ORs together, the summarized OR was 1.29 [95% confidence interval (CI) =1.00-1.67]. The summarized OR for the Asian group 1.50 (95% CI = 1.35-1.67) was significantly higher than that of Caucasian group 1.08 (95% CI = 0.39-2.97). Eleven studies have provided the data on association between handgrip strength and hypertension. The overall OR and 95% CI was 0.99 (95% CI = 0.80-1.23), showing no significant association. CONCLUSION: Sarcopenia was associated with hypertension, but no correlation was found between handgrip strength and hypertension in older adults.

Quantitative analysis of direct oral anticoagulant rivaroxaban by terahertz spectroscopy.

Rivaroxaban, as a direct oral anticoagulant, has been widely used in the treatment and prevention of thrombosis disease (TD). However, even if the same dose of rivaroxaban is taken, different pathophysiological characteristics of TD patients determine the differences in plasma concentrations between individuals, leading to the difficulties of dosage selection and plasma concentration control. Conventional rivaroxaban detection methods, including prothrombin time method, anti-Xa assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS), are not widely used in clinical practice due to the limitations of accuracy, speed and cost. Here, we present a simple quantitative detection method for rivaroxaban by terahertz (THz) spectroscopy. Combining density functional theory (DFT) method and THz spectroscopy, the THz absorption peaks of rivaroxaban and the corresponding low-frequency vibrational modes are studied theoretically and experimentally. We find linear relationships between the amplitudes of these characteristic peaks and the concentrations of rivaroxaban. Based on these linear functions, we can analyse the rivaroxaban concentration with a detection time of 1 minute per test and the lowest detection limit of 2 µmol mL-1. As compared to Raman spectroscopy method (its detection limit is about 80 µmol mL-1), our method has more potential and is practical for the clinical quantitative detection of rivaroxaban as well as other direct oral anticoagulants.

Effect of HIF-1α/miR-10b-5p/PTEN on Hypoxia-Induced Cardiomyocyte Apoptosis.

Background Few reports have addressed the mechanism by which microRNA miR-10b-5p regulates post-myocardial infarction (post-MI) cardiomyocyte apoptosis under hypoxic conditions. Methods and Results C57BL/6 mice underwent surgical ligation of the left anterior descending artery to create an MI or ischemia/reperfusion animal model. The expression of miR-10b-5p, PTEN (phosphatase and tensin homolog), and HIF-1α (hypoxia-inducible factor 1α) was detected in infarct border zone tissues at various time points. After precordial injections of the negative control or miR-10b-5p, overexpression lentiviruses were made in the areas surrounding the MI sites at 1 week, and myocardial infarct size, cardiac function, and cardiomyocyte apoptosis were examined. A miR-10b-5p mimic was transfected into primary mouse cardiomyocytes to analyze its effects on cardiomyocyte apoptosis and PTEN expression. Meanwhile, PTEN as a target of miR-10b-5p was verified via luciferase reporter gene assays. Cotransfection of miR-10b-5 and PTEN verified the relationship between miR-10b-5 and PTEN. Under hypoxic stress, the expression of HIF-1α and miR-10b-5p was examined. The results showed that miR-10b-5p expression was markedly reduced in the infarct border zone. Overexpression of miR-10b-5p in the murine model of MI significantly reduced MI size, improved cardiac function, and inhibited apoptosis. Overexpression of miR-10b-5p in vitro antagonized hypoxia-induced cardiomyocyte apoptosis and specifically inhibited the expression of the apoptosis-related gene PTEN, but overexpression of PTEN weakened these effects. We also found that hypoxia-induced accumulation of HIF-1α resulted in decreased expression of miR-10b-5p. Interfering with the activation of the HIF-1α signaling pathway promoted Pri-miR-10b and miR-10b-5p expression and inhibited PTEN expression. Conclusions MicroRNA miR-10b-5p antagonizes hypoxia-induced cardiomyocyte apoptosis, indicating that miR-10b-5p may serve as a potential future clinical target for the treatment of MI.

Loss of miR-146b-3p Inhibits Perivascular Adipocyte Browning with Cold Exposure During Aging.

PURPOSE: Pathological changes of the perivascular adipose tissue (PVAT) are directly associated with increased risk of age-related vascular diseases. MicroRNAs regulate adipocyte biological functions including adipogenic differentiation and white adipocyte browning. The present study aims to determine whether miR-146b-3p is involved in the regulation of perivascular adipocyte browning during aging. METHODS: We utilized a cold-induced animal model to investigate the effect of aging on perivascular adipocyte browning. We also detected the miR-146b-3p expression in the PVAT of young or old mice after cold stimulus. We further investigated the role of miR-146b-3p in regulating perivascular adipocyte browning in vitro and in vivo via administrating miRNA mimics or inhibitors. RESULTS: Old mice showed decrease of perivascular adipocyte browning and downregulation of miR-146b-3p expression in the PVAT after cold stimulus. Oil red O staining and qPCR indicated that aging perturbed preadipocyte to brown adipocyte differentiation, and expression of miR-146b-3p gradually increased during differentiation. MiR-146b-3p inhibitors blocked brown adipocyte differentiation in young preadipocytes, whereas miR-146b-3p mimics rescued the differentiation of the old preadipocytes. Finally, miR-146b-3p knocks down inhibited perivascular adipocyte browning in young mice after cold stimulus. CONCLUSION: Aging inhibits perivascular adipocyte browning, and loss of miR-146b-3p is a potential regulator for this process.

MicroRNA-146b-3p regulates the development and progression of cerebral infarction with diabetes through RAF1/P38MAPK/COX-2 signaling pathway.

Diabetes has been considered as an independent risk factor for cerebral infarction. However, the pathological mechanism of cerebral infarction with diabetes (DMCI) is still rarely known. In this study, we try to explore the relationship between microRNA-146b-3p (miR-146b-3p) and DMCI patients. The peripheral blood mononuclear cells were separated after the patients were selected from our hospital. Firstly, the content of IL-6 and COX-2 was detected by ELISA. Then, the total RNAs were extracted and analyzed by microRNA (miRNA) microarray. Moreover, the target genes of miR-146b-3p were predicted by online miRNA target prediction algorithms. Meanwhile, luciferase reporter system was used for assaying the target gene for miRNA-146b-3p. Simultaneously, RT-PCR assay was used for the miRNA expression detection. Furthermore, western blot was applied to determine the expression of the signal pathway involved proteins. Our results demonstrated that expression of IL-6 and COX-2 were remarkably up-regulated in peripheral blood of DMCI patients compared with that in normal control group. In addition, miRNA microarray data suggested that miR-146b-3p expression was significantly down-regulated in DMCI patients, with v-raf-1 expression negatively regulated. Moreover, miR-146b-3p regulated RAF1 expression was found to mediate P38MAPK signaling activation in thrombosis patients. The following research indicated that activation of RAF1 trough miR-146b-3p down-regulation contributed to activation of RAF/P38MAPK/COX-2 signaling pathway in vascular infarction. Our data have implied that altered expression of miR-146b-3p is closely related to the progression and development of DCMI mediating the RAF/P38MAPK/COX-2 signal transduction pathway.

Rapamycin inhibits CaCl2-induced thoracic aortic aneurysm formation in rats through mTOR-mediated suppression of proinflammatory mediators.

The aim of the present study was to investigate the effect of the mammalian target of rapamycin (mTOR) signaling pathway on thoracic aortic aneurysm (TAA) development. The study used a calcium chloride (CaCl2)­induced rat TAA model to explore the potential role of mTOR signaling pathway in the disease development. Adult male Sprague­Dawley rats underwent the periarterial exposure of thoracic aorta to either 0.5 M CaCl2 or normal saline, and a subgroup of CaCl2­treated rats received rapamycin 1 day prior to surgery. Without pre­administering rapamycin, significantly enhanced phosphorylation of mTOR and expression of proinflammatory cytokines [i.e., tumor necrosis factor α (TNF­α), interleukin 6 (IL­6), and interleukin (IL)­1ß] were observed in the CaCl2­treated aortic segments 2 days post­treatment compared with the NaCl­treated segments. At 2 weeks post­treatment, hematoxylin and eosin and Verhoeff­Van Gieson staining revealed aneurysmal alteration and disappearance of normal wavy elastic structures in the aortic segments exposed to CaCl2. In contrast, the CaCl2­induced TAA formation was inhibited by pre­administering rapamycin to CaCl2­treated rats, which demonstrated attenuated mTOR phosphorylation and downregulation of the proinflammatory mediators (i.e., TNF­α, IL­6, IL­1ß, matrix metallopeptidases 2 and 9) to the control level. Further in vitro cell culture experiments using aortic smooth muscle cell (SMC) suggested that the inhibition of the mTOR signaling pathway by rapamycin could promote the differentiation of SMCs, as reflected by the reduced expression of S100A4 and osteopontin. The present study indicated that the early enhanced mTOR signaling pathway in the TAA development and mTOR inhibitor rapamycin may inhibit CaCl2­induced TAA formation.

Pulmonary enteric adenocarcinoma with pancreatic metastasis: A case report.

Pulmonary enteric adenocarcinoma is a markedly rare pathological type of lung adenocarcinoma. As the pancreas is a relatively uncommon site for metastasis, the present case is even more unusual. A 62-year-old male was admitted to hospital following the identification of masses in the left chest wall, right abdominal wall and right upper limb, but with no respiratory symptoms. Computed tomography (CT) of the chest revealed a lump in the lung and a mass in the left chest wall, and 18F-fluorodeoxyglucose (18F-FDG) uptake by the lumps was increased. An enhanced abdominal CT revealed a hypodense and homogeneous mass on the head of the pancreas, which was slightly enhanced compared with normal pancreatic tissue. In addition, the 18F-FDG uptake of the lesion was increased and the standardized uptake value (SUV) delayed was not evidently decreased compared with SUVearly. A number of other abnormal metabolic lesions were also identified using positron emission tomography/CT, whereas no abnormal 18F-FDG uptake was identified in the gastrointestinal organ. Furthermore, rectocolonoscopy was performed to exclude diagnosis of metastatic colorectal adenocarcinoma. The hematoxylin- and eosin-stained smears of the masses in the right lung and left chest demonstrated an enteric pattern, which shared morphological and immunohistochemical (IHC) features with those of colorectal adenocarcinoma. The IHC detection revealed that the lesions in the right lung were positive for cytokeratin 7 (CK7), and negative for CK20 and thyroid transcription factor 1 (TTF-1), and the expression of caudal type homeobox 2 (CDX2) was weakly positive; the masses in the left chest wall were positive for CK7, negative for TTF-1, and CK20 and CDX2 were weakly expressed.

Loss of Smooth Muscle α-Actin Leads to NF-κB-Dependent Increased Sensitivity to Angiotensin II in Smooth Muscle Cells and Aortic Enlargement.

RATIONALE: Mutations in ACTA2, encoding the smooth muscle isoform of α-actin, cause thoracic aortic aneurysms, acute aortic dissections, and occlusive vascular diseases. OBJECTIVE: We sought to identify the mechanism by which loss of smooth muscle α-actin causes aortic disease. METHODS AND RESULTS: Acta2-/- mice have an increased number of elastic lamellae in the ascending aorta and progressive aortic root dilation as assessed by echocardiography that can be attenuated by treatment with losartan, an angiotensin II (AngII) type 1 receptor blocker. AngII levels are not increased in Acta2-/- aortas or kidneys. Aortic tissue and explanted smooth muscle cells from Acta2-/- aortas show increased production of reactive oxygen species and increased basal nuclear factor κB signaling, leading to an increase in the expression of the AngII receptor type I a and activation of signaling at 100-fold lower levels of AngII in the mutant compared with wild-type cells. Furthermore, disruption of smooth muscle α-actin filaments in wild-type smooth muscle cells by various mechanisms activates nuclear factor κB signaling and increases expression of AngII receptor type I a. CONCLUSIONS: These findings reveal that disruption of smooth muscle α-actin filaments in smooth muscle cells increases reactive oxygen species levels, activates nuclear factor κB signaling, and increases AngII receptor type I a expression, thus potentiating AngII signaling in vascular smooth muscle cells without an increase in the exogenous levels of AngII.

Spatiotemporal expression of matrix metalloproteinases (MMPs) is regulated by the Ca2+-signal transducer S100A4 in the pathogenesis of thoracic aortic aneurysm.

AIMS: This study investigated whether S100A4 plays a potential role in the formation of thoracic aortic aneurysm (TAA). METHODS AND RESULTS: The thoracic aortas of male Sprague-Dawley rats were exposed to 0.5 M CaCl2 or normal saline (NaCl). Animals were euthanized at specified time-points (2, 4, and 10 weeks post-TAA induction). The treated aortic segments were harvested, and mRNA levels, protein expressions and immunohistochemistry of MMP-2, MMP-9 and S100A4 were analyzed. The A7r5 cell lines were used for an in vitro study. Experiments were also performed using human TAA samples for comparison. Localized aneurysmal dilation was observed in the CaCl2-treated segments. The transcription levels of S100A4 and MMPs were elevated in CaCl2-treated segments versus controls, and a significant correlation between S100A4 and expression of MMPs was observed across all time-points. Immunohistochemical studies revealed similar expression pattern of S100A4 and MMP proteins, as well as co-localization of S100A4 with the cell lineage markers (αSMA and CD68) and inflammatory markers (MMPs and NF-κB P65 subunit). The proliferative ability of A7r5 cells after transfection with S100A4 siRNA was suppressed, and down-regulation of S100A4 inhibited MMP-2 and MMP-9 expression in vitro. Increased expression of S100A4 was observed in all layers of the aorta wall in human TAA specimens. Serum concentrations of S100A4 determined by ELISA were found to be significantly increased in TAA patients. CONCLUSIONS: This study established the important roles of S100A4 and MMPs in the development of TAA.

Aortic remodeling after transverse aortic constriction in mice is attenuated with AT1 receptor blockade.

OBJECTIVE: Although hypertension is the most common risk factor for thoracic aortic diseases, it is not understood how increased pressures on the ascending aorta lead to aortic aneurysms. We investigated the role of angiotensin II type 1 receptor activation in ascending aortic remodeling in response to increased biomechanical forces using a transverse aortic constriction (TAC) mouse model. APPROACH AND RESULTS: Two weeks after TAC, the increased biomechanical pressures led to ascending aortic dilatation and thickening of the medial and adventitial layers of the aorta. There was significant adventitial hyperplasia and inflammatory responses in TAC ascending aortas were accompanied by increased adventitial collagen, elevated inflammatory and proliferative markers, and increased cell density attributable to accumulation of myofibroblasts and macrophages. Treatment with losartan significantly blocked TAC-induced vascular inflammation and macrophage accumulation. However, losartan only partially prevented TAC-induced adventitial hyperplasia, collagen accumulation, and ascending aortic dilatation. Increased Tgfb2 expression and phosphorylated-Smad2 staining in the medial layer of TAC ascending aortas were effectively blocked with losartan. In contrast, the increased Tgfb1 expression and adventitial phospho-Smad2 staining were only partially attenuated by losartan. In addition, losartan significantly blocked extracellular signal-regulated kinase activation and reactive oxygen species production in the TAC ascending aorta. CONCLUSIONS: Inhibition of the angiotensin II type 1 receptor using losartan significantly attenuated the vascular remodeling associated with TAC but did not completely block the increased transforming growth factor-ß1 expression, adventitial Smad2 signaling, and collagen accumulation. These results help to delineate the aortic transforming growth factor-ß signaling that is dependent and independent of the angiotensin II type 1 receptor after TAC.

Smooth muscle hyperplasia due to loss of smooth muscle α-actin is driven by activation of focal adhesion kinase, altered p53 localization and increased levels of platelet-derived growth factor receptor-ß.

Mutations in ACTA2, encoding the smooth muscle cell (SMC)-specific isoform of α-actin (α-SMA), cause thoracic aortic aneurysms and dissections and occlusive vascular diseases, including early onset coronary artery disease and stroke. We have shown that occlusive arterial lesions in patients with heterozygous ACTA2 missense mutations show increased numbers of medial or neointimal SMCs. The contribution of SMC hyperplasia to these vascular diseases and the pathways responsible for linking disruption of α-SMA filaments to hyperplasia are unknown. Here, we show that the loss of Acta2 in mice recapitulates the SMC hyperplasia observed in ACTA2 mutant SMCs and determine the cellular pathways responsible for SMC hyperplasia. Acta2(-/-) mice showed increased neointimal formation following vascular injury in vivo, and SMCs explanted from these mice demonstrated increased proliferation and migration. Loss of α-SMA induced hyperplasia through focal adhesion (FA) rearrangement, FA kinase activation, re-localization of p53 from the nucleus to the cytoplasm and increased expression and ligand-independent activation of platelet-derived growth factor receptor beta (Pdgfr-ß). Disruption of α-SMA in wild-type SMCs also induced similar cellular changes. Imatinib mesylate inhibited Pdgfr-ß activation and Acta2(-/-) SMC proliferation in vitro and neointimal formation with vascular injury in vivo. Loss of α-SMA leads to SMC hyperplasia in vivo and in vitro through a mechanism involving FAK, p53 and Pdgfr-ß, supporting the hypothesis that SMC hyperplasia contributes to occlusive lesions in patients with ACTA2 missense mutations.

Detection and validation of circulating endothelial cells, a blood-based diagnostic marker of acute myocardial infarction.

BACKGROUND: Circulating endothelial cells (CECs) are markers of vascular damage that have clinical relevance in many diseases, including acute myocardial infarction (AMI), and may be predictors of treatment responses. Herein, we investigated the diagnostic and prognostic value of CEC monitoring in AMI patients and a murine model. METHODOLOGY/PRINCIPAL FINDINGS: CECs were defined as Hoechst 33342(+)/CD45(-/)CD31(+)/CD146(+)/CD133(-) in human blood samples and Hoechst 33342(+)/CD45(-/)CD31(+)/KDR(+)/CD117(-) in murine samples. To evaluate the validity and variability of our CEC detection system, peripheral blood samples of vascular endothelial growth factor-treated athymic nude mice and AMI patients were collected and subjected to intra-assay analysis. CEC detection by flow cytometry and real-time PCR were compared. Blood samples were obtained from 61 AMI patients, 45 healthy volunteers and 19 samples of the original AMI patients accepted one month treatment, via flow cytometry and expressed as a percentage of peripheral blood mononuclear cells. RESULTS: Our CEC detection method was validated and had limited variability. CEC concentrations were higher in AMI patients compared to healthy controls. One month post-treatment, CECs levels decreased significantly. CONCLUSIONS/SIGNIFICANCE: CEC levels may be useful as a diagnostic and prognostic biomarker in AMI patients.

Recurrent chromosome 16p13.1 duplications are a risk factor for aortic dissections.

Chromosomal deletions or reciprocal duplications of the 16p13.1 region have been implicated in a variety of neuropsychiatric disorders such as autism, schizophrenia, epilepsies, and attention-deficit hyperactivity disorder (ADHD). In this study, we investigated the association of recurrent genomic copy number variants (CNVs) with thoracic aortic aneurysms and dissections (TAAD). By using SNP arrays to screen and comparative genomic hybridization microarrays to validate, we identified 16p13.1 duplications in 8 out of 765 patients of European descent with adult-onset TAAD compared with 4 of 4,569 controls matched for ethnicity (P = 5.0 × 10⁻5, OR = 12.2). The findings were replicated in an independent cohort of 467 patients of European descent with TAAD (P = 0.005, OR = 14.7). Patients with 16p13.1 duplications were more likely to harbor a second rare CNV (P = 0.012) and to present with aortic dissections (P = 0.010) than patients without duplications. Duplications of 16p13.1 were identified in 2 of 130 patients with familial TAAD, but the duplications did not segregate with TAAD in the families. MYH11, a gene known to predispose to TAAD, lies in the duplicated region of 16p13.1, and increased MYH11 expression was found in aortic tissues from TAAD patients with 16p13.1 duplications compared with control aortas. These data suggest chromosome 16p13.1 duplications confer a risk for TAAD in addition to the established risk for neuropsychiatric disorders. It also indicates that recurrent CNVs may predispose to disorders involving more than one organ system, an observation critical to the understanding of the role of recurrent CNVs in human disease and a finding that may be common to other recurrent CNVs involving multiple genes.