Diastolic and systolic blood pressure time in target range as a cardiovascular risk marker in patients with type 2 diabetes: A post hoc analysis of ACCORD BP trial.

AIMS: We investigated the associations between time in target range (TTR) of blood pressure (BP) and cardiovascular outcomes in patients with diabetes. METHODS: 4651 participants from the Action to Control Cardiovascular Risk in Diabetes (ACCORD) BP trial were included in the present study. The diastolic BP target range was defined as 70 to 80 mm Hg, and the systolic as 120 to 140 mm Hg and 110 to 130 mm Hg for the standard and intensive therapy, respectively. RESULTS: After adjusting for covariates, 1-SD increase of diastolic TTR was significantly associated with lower risks of primary outcome (HR 0.82, 95% CI: 0.74-0.91, P < 0.001; HR 0.86, 95% CI: 0.77-0.95, P = 0.0044, as well as nonfatal myocardial infarction (HR 0.79, 95% CI: 0.69-0.91, P < 0.001). Meanwhile, systolic TTR was significantly associated with various cardiovascular outcomes (P ≤ 0.016) in fully-adjusted models. The diastolic TTR sustained significance in myocardial infarction when systolic blood pressure average was higher than 120 mm Hg. CONCLUSIONS: In patients with diabetes, TTR of diastolic and systolic BP was independently associated with lower risks of major outcomes. The diastolic BP within the optimal target range was considerably important for reducing the risk of myocardial infarction, even when systolic BP was under stable control.

Cancer-associated fibroblasts promote oral squamous cell carcinoma progression through LOX-mediated matrix stiffness.

BACKGROUND: Cancer-associated fibroblasts (CAFs), the most abundant cells in the tumor microenvironment, have prominent roles in the development of solid tumors as stromal targets. However, the underlying mechanism of CAFs' function in oral squamous cell carcinoma (OSCC) development remains unclear. Here, we investigated the role of lysyl oxidase (LOX) expression in CAFs in tumor stromal remodeling and the mechanism of its effect on OSCC progression. METHODS: Multiple immunohistochemistry (IHC) staining was performed to detect the correlation of CAFs and LOX in the stroma of OSCC specimens, as well as the correlation with clinicopathological parameters and prognosis. The expression of LOX in CAFs were detected by RT-qPCR and western blot. The effects of LOX in CAFs on the biological characteristics of OSCC cell line were investigated using CCK-8, wound-healing and transwell assay. CAFs were co-cultured with type I collagen in vitro, and collagen contraction test, microstructure observation and rheometer were used to detect the effect of CAFs on remodeling collagen matrix. Then, collagen with different stiffness were established to investigate the effect of matrix stiffness on the progression of OSCC. Moreover, we used focal adhesion kinase (FAK) phosphorylation inhibitors to explored whether the increase in matrix stiffness promote the progression of OSCC through activating FAK phosphorylation pathway. RESULTS: LOX was colocalized with CAFs in the stroma of OSCC tissues, and its expression was significantly related to the degree of malignant differentiation and poor prognosis in OSCC. LOX was highly expressed in CAFs, and its knockdown impaired the proliferation, migration, invasion and EMT process of OSCC cells. The expression of LOX in CAFs can catalyze collagen crosslinking and increase matrix stiffness. Furthermore, CAFs-derived LOX-mediated increase in collagen stiffness induced morphological changes and promoted invasion and EMT process in OSCC cells by activating FAK phosphorylation pathway. CONCLUSIONS: Our findings suggest that CAFs highly express LOX in the stroma of OSCC and can remodel the matrix collagen microenvironment, and the increase in matrix stiffness mediated by CAFs-derived LOX promotes OSCC development through FAK phosphorylation pathway. Thus, LOX may be a potential target for the early diagnosis and therapeutic treatment of OSCC.

Upregulation of CSF-1 is correlated with elevated TAM infiltration and poor prognosis in oral squamous cell carcinoma.

Mounting lines of evidence indicated that the "colony stimulating factor-1 (CSF-1)/tumor-associated macrophage (TAM)" signature plays an important role in the progression, invasion and metastasis of multiple tumors. However, the potential role of CSF-1/TAM in oral squamous cell carcinoma (OSCC) remains largely unknown. In the present study, the expression of CSF-1 from 99 OSCC specimens and its correlation with clinicopathological features and patient outcomes were investigated. Meanwhile, the correlation between CSF-1 expression and TAM infiltration was also explored. To investigate the potential effect of CSF-1 on tumor growth, nude mice were subcutaneously injected with Cal27 cell line and a small molecule inhibitor of CSF-1 (BZL945). The results showed that the high expression rate of CSF-1 (52%) was found in OSCC, and the upregulation of CSF-1 was closely correlated with lymph node metastasis and clinical stage. Additionally, there was a positive correlation between a high CSF-1 level and elevated TAM infiltration. The xenograft model study showed that CSF-1 signal blockade inhibited tumor growth, with a significant synchronous decrease in CSF-1 expression and TAM infiltration. Overall, our findings indicated that CSF-1 plays a crucial role in TAMs-mediated OSCC tumor progression and invasion. The "CSF-1/TAM" signaling axis may serve as a prospective target for anti-tumor therapy of OSCC.

Heat shock factor 1 in cancer-associated fibroblasts is a potential prognostic factor and drives progression of oral squamous cell carcinoma.

Heat shock factor 1 (HSF1) is highly expressed in various malignancies and is a potential modulator of tumor progression. Emerging evidence suggests that HSF1 activation in stromal cells is closely related to poor patient prognosis. However, the role of HSF1 in oral squamous cell carcinoma (OSCC) remains elusive. We aimed to investigate the function of HSF1 in cancer-associated fibroblasts (CAFs) of the tumor microenvironment (TME) and in tumor development. In the present study, we found that HSF1 was highly expressed in both CAFs and tumor cells, and was significantly correlated with poor prognosis and overall survival. Moreover, HSF1 overexpression in CAFs resulted in a fibroblast-like phenotype of Cal27 cells, induced epithelial-mesenchymal transition (EMT), and promoted proliferation, migration and invasion in Cal27 cells. HSF1 knockdown attenuated features of CAFs and reduced EMT, proliferation, migration and invasion in Cal27 cells. Furthermore, HSF1 in CAFs promoted tumor growth in nude mice. Taken together, these data suggest that HSF1 expression in CAFs drive OSCC progression, and could serve as an independent prognostic marker of patients with OSCC. Thus, HSF1 is a potent mediator of OSCC malignancy.

TLR2 deficiency enhances susceptibility to oral carcinogenesis by promoting an inflammatory environment.

Inflammation is closely related to oral squamous cell carcinoma (OSCC). However, its mechanism is still obscure. Toll-like receptor 2 (TLR2) plays an important role in oral chronic inflammatory diseases, but the role of TLR2 in OSCC is unclear. Here, we investigated the expression of TLR2 expression in OSCCs and examined the potential role of TLR2 in OSCC through its association with clinicopathological features and patient outcome. We used 4-nitroquinoline 1-oxide (4-NQO) to induce a tongue cancer model in TLR2-/- and wild type (WT) mice. Histological and clinical results both indicated that TLR2 played a protective role in oral tumorigenesis. The results of a cytometric bead array (CBA) indicated that TLR2 deficiency resulted in Th1 and Th2 cytokine abnormalities, especially Th2 abnormalities. Immunohistochemistry also showed that TLR2 deficiency increases the number of tongue-infiltrating M2 macrophages. Overall, our results demonstrated that TLR2 plays an important role in the prevention of oral tumorigenesis and affects the levels of Th2 cytokines and tongue-infiltrating M2 macrophages; therefore, it may be used to prevent the development of oral cancer.

Suppression of Endothelial-to-Mesenchymal Transition by SIRT (Sirtuin) 3 Alleviated the Development of Hypertensive Renal Injury.

Endothelial-to-mesenchymal transition (EndoMT) has recently emerged as a potentially important contributor in promoting fibrosis in chronic kidney disease. However, little is known about the role and molecular basis of its involvement in hypertensive renal injury. Here, we aim to determine the role of SIRT (sirtuin) 3 on EndoMT in hypertensive renal injury and to explore its underlying mechanisms. We found that SIRT3 expression was significantly reduced in Ang II (angiotensin II)-induced hypertensive model, accompanied with induction of EndoMT and increased reactive oxygen species and renal fibrosis. In SIRT3-/- (SIRT3 knockout) mice subjected to Ang II infusion, renal dysfunction was aggravated with an increased EndoMT and reactive oxygen species level, whereas in SIRT3-TgEC (SIRT3 endothelial cell-specific transgenic) mice, the Ang II-induced renal fibrosis and EndoMT and oxidative stress were ameliorated. With primary mouse glomerular endothelial cells, we confirmed that Ang II treatment initiated EndoMT and decreased catalase expression, which were suppressed by SIRT3 overexpression. Using immunoprecipitation, luciferase, and chromatin immunoprecipitation assay, we demonstrated that SIRT3-mediated deacetylation and nuclear localization of Foxo3a (forkhead box O3a) resulted in activated Foxo3a-dependent catalase expression. Moreover, Foxo3a knockdown abolished SIRT3-mediated suppression of EndoMT. In conclusion, these results established the SIRT3-Foxo3a-catalase pathway as a critical factor in the maintenance of endothelial homeostasis and point to an important role of EndoMT in the vascular pathology of renal fibrosis, which may provide a new therapeutic target to impede the progression of hypertensive renal injury.

Downregulation of dynamin-related protein 1 contributes to impaired autophagic flux and angiogenic function in senescent endothelial cells.

OBJECTIVE: Recent studies have shown that altered mitochondrial dynamics impairs the function in senescent endothelial cells (ECs). However, the underlying molecular mechanism remains to be elucidated. Herein, we investigated the role and underlying mechanism of mitochondrial fission protein dynamin-related protein 1 (DRP1) in vascular aging. APPROACH AND RESULTS: We found that DRP1 expression is decreased in senescent ECs, accompanied with long interconnected mitochondria and impaired angiogenic function. In addition, there was marked increase of autophagosomes but not of autolysosomes (assessed as punctate dual fluorescent mCherry-GFP (green fluorescent protein) tandem-tagged light chain 3 expression) in senescent ECs, indicating impaired autophagic flux. DRP1 knockdown or pharmacological inhibition in young ECs resulted in elongated mitochondria, suppressed autophagic flux, premature senescence, and impaired angiogenic function. In contrast, adenoviral-mediated overexpression of DRP1 in senescent ECs restored autophagic flux and improved angiogenic function. EC senescence was associated with the increase of mitochondrial reactive oxygen species and antioxidant N-acetyl-cysteine restored autophagosome clearance and improved angiogenic function. Consistently, en face staining of old rat thoracic aorta revealed a decrease of DRP1 expression and increase of autophagosomes accumulation. Furthermore, in vivo knockdown of Drp1 in common carotid arteries significantly impaired the autophagosome clearance. Importantly, downregulation of Drp1 directly abrogated microvessels outgrowth from ex vivo aortic rings. CONCLUSIONS: These results suggest that loss of DRP1 during senescence exacerbates ECs dysfunction by increasing mitochondrial reactive oxygen species and subsequently inhibiting autophagic flux.

Differential changes of aorta and carotid vasodilation in type 2 diabetic GK and OLETF rats: paradoxical roles of hyperglycemia and insulin.

We investigated large vessel function in lean Goto-Kakizaki diabetic rats (GK) and Otsuka Long-Evans Tokushima Fatty diabetic rats (OLETF) with possible roles of hyperglycemia/hyperosmolarity and insulin. Both young and old GK showed marked hyperglycemia with normal insulin level and well-preserved endothelium-dependent and endothelium-independent vasodilation in aorta and carotid artery. There were significant elevations in endothelial/inducible nitric oxide synthase (eNOS/iNOS) and inducible/constitutive heme oxygenase (HO-1/HO-2) in GK. The endothelium-dependent vasodilation in GK was inhibited partly by NOS blockade and completely by simultaneous blocking of HO and NOS. In contrast, OLETF showed hyperinsulinemia and mild hyperglycemia but significant endothelium dysfunction beginning at early ages with concomitantly reduced eNOS. Insulin injection corrected hyperglycemia in GK but induced endothelium dysfunction and intima hyperplasia. Hyperglycemia/hyperosmolarity in vitro enhanced vessel eNOS/HO. We suggest that hyperinsulinemia plays a role in endothelium dysfunction in obese diabetic OLETF, while hyperglycemia/hyperosmolarity-induced eNOS/HO upregulation participates in the adaptation of endothelium function in lean diabetic GK.

Paradoxical effects of streptozotocin-induced diabetes on endothelial dysfunction in stroke-prone spontaneously hypertensive rats.

Although both diabetes and hypertension are risk factors for cardiovascular disease, the role of hyperglycaemia per se in endothelial dysfunction is controversial. This study was designed to examine whether hyperglycaemia, or streptozotocin-induced diabetes, could aggravate endothelial dysfunction in stroke-prone spontaneously hypertensive rats (SHRSP). Hyperglycaemia was induced by streptozotocin in 2-month-old SHRSP and age-matched normotensive Wistar-Kyoto (WKY) rats. The aorta was isolated 8 weeks after induction of hyperglycaemia to record its function and to examine its morphology with transmission electron microscopy. Endothelial/inducible nitric oxide synthase (eNOS/iNOS) and inducible/constitutive haem oxygenase (HO-1/HO-2) levels were determined with Western blotting. Aortic endothelial function and production of reactive oxygen species and nitric oxide were assayed after incubation in vitro in hyperglycaemic, hyperosmolar solution. Streptozotocin-induced diabetes of 8 weeks duration did not result in endothelial dysfunction in normotensive WKY rats. In contrast, hyperglycaemic WKY rats showed significantly enhanced endothelium-dependent vasodilatation, which was abrogated by simultaneous blocking of NOS and HO. The enhanced vasodilatation was associated with elevation of vascular eNOS and HO-1. Significant endothelial dysfunction and massive macrophage-monocyte infiltration were found in SHRSP aorta (the ratio of the number of macrophages to endothelial cells in the intima, expressed as a percentage, was 20.9 ± 2.8% in SHRSP versus 1.9 ± 0.5% in WKY rats, P < 0.01), which was attenuated significantly in hyperglycaemic SHRSP (11.3 ± 1.6%, P < 0.01 versus SHRSP). Acute hyperglycaemia (10 min) aggravated endothelial dysfunction in SHRSP, with a marked increase in intracellular reactive oxygen species and NO production. Sustained in vitro incubation in hyperglycaemic/hyperosmolar conditions (addition of an extra 50 mmol L(-1) of glucose or mannitol to the usual buffer, to produce a final osmolarity of 350 mosmol L(-1)) for 5 h enhanced endothelium-dependent vasodilatation, with elevated vessel NO production and upregulation of eNOS/HO-1 proteins. Sustained hyperglycaemia does not aggravate endothelial dysfunction and macrophage infiltration in SHRSP. Hyperglycaemia/hyperosmolarity-induced upregulation of eNOS and HO-1 may play a role in this paradoxical adaptation of endothelial function.

MicroRNA-155 regulates angiotensin II type 1 receptor expression and phenotypic differentiation in vascular adventitial fibroblasts.

MicroRNAs (miRNAs), which are genomically encoded small RNAs, negatively regulate target gene expression at the post-transcriptional level. Our recent study indicated that microRNA-155 (miR-155) might be negatively correlated with blood pressure, and it has been suggested that miR-155-mediated target genes could be involved in the cardiovascular diseases. Bioinformatic analyses predict that angiotensin II type 1 receptor (AT(1)R) is a miR-155 target gene. The present study investigated the potential role of miR-155 in regulating AT(1)R expression and phenotypic differentiation in rat aortic adventitial fibroblasts (AFs). Luciferase assay demonstrated that miR-155 suppressed AT(1)R 3'-UTR reporter construct activity. miR-155 overexpression in AFs did not reduce target mRNA levels, but significantly reduced target protein expression. In addition, AFs transfected with pSUPER/miR-155 exhibited reduced Ang II-induced ERK1/2 activation. miR-155 overexpression in cells attenuated Ang II-induced α-smooth muscle actin (α-SMA, produces myofibroblast) expression, but did not transform growth factor beta-1 (TGF-ß1). This study demonstrated that miR-155 could have an important role in regulating adventitial fibroblast differentiation and contribute to suppression of AT(1)R expression.

2-(2-Methoxy-phen-yl)butane-dinitrile.

In the title compound, C(11)H(10)N(2)O, the butane-dinitrile unit adopts a synclinal conformation. The crystal packing is stabilized by weak inter-molecular C-H⋯N hydrogen bonding.

(E)-Ethyl 3-(3-bromo-phen-yl)-2-cyano-acrylate.

The title mol-ecule, C(12)H(10)BrNO(2), adopts an E configuration with respect to the C=C bond of the acrylate unit. In the crystal structure, mol-ecules are connected by a pair of inter-molecular C-H⋯O hydrogen bonds, forming a centrosymmetric dimer.

Angiotensin II-stimulated collagen synthesis in aortic adventitial fibroblasts is mediated by connective tissue growth factor.

Angiotensin II (Ang II), a potent mediator of vascular remodeling, can stimulate the synthesis of extracellular matrix in vascular cells. Recent studies indicate that connective tissue growth factor (CTGF) is involved in collagen synthesis. There is also increasing evidence that adventitial fibroblasts (AFs) are actively involved in vascular remodeling. However, whether collagen synthesis by AFs is mediated by CTGF, or whether it is relevant to Ang II, has not been studied. The present study was conducted to determine whether CTGF is expressed in AFs, and if so, whether the CTGF produced by AFs participates in collagen synthesis. The AFs were isolated from thoracic aorta of Wistar-Kyoto rats (WKY). The expression of CTGF was measured by Western blot or real-time PCR. Collagen synthesis was assessed by [(3)H]proline incorporation. Our results suggested that CTGF was expressed in AFs and secreted into medium. Ang II increased CTGF mRNA and protein expression in a time- and dose-dependent manner, with the maximal protein increase occurring at 24 h with an Ang II dose of 10(-7) mol/L, and this increase was inhibited by the Ang II receptor type 1 (AT(1)-R) antagonist losartan, but not by the Ang II receptor type 2 (AT(2)-R) antagonist PD123319. Ang II dose-dependently stimulated the incorporation of [(3)H]proline into cultured AFs, and this effect was inhibited by a CTGF antisense oligodeoxynucleotide. Overexpression of CTGF by pcDNA3.1(+)/CTGF increased [(3)H]proline incorporation in cultured AFs. The results demonstrated that, in cultured AFs, Ang II increased CTGF production via AT(1)-R, which could be mediators of collagen synthesis by Ang II. This finding suggests that CTGF might be a novel target for antifibrotic therapy in vascular diseases.

Elevated catalase and heme oxygenase-1 may contribute to improved postischaemic cardiac function in long-term type 1 diabetes.

1. Although increased oxidative stress has been shown repeatedly to be implicated in diabetes, the cardiovascular anti-oxidant state and heart response to ischaemia in long-term Type 1 diabetes remain largely unknown. The present study was designed to observe heart tolerance to ischaemia-reperfusion and endogenous anti-oxidants in the cardiovascular system in long-term hyperglycaemic rats. 2. Hearts from Sprague-Dawley rats surviving up to 6 months with streptozocin-induced severe hyperglycaemia (blood glucose > 20 mmol/L) were isolated and subjected to global ischaemia and reperfusion. Cardiac function, electrocardiogram and anti-oxidants in the myocardium and aorta were examined. In addition, the morphology of the myocardial mitochondria and the in vitro function of aortic vessels were assessed. 3. Hearts from diabetic rats demonstrated lower baseline heart function but had higher postischaemic coronary flow and left ventricular developed pressure compared with their respective controls (P < 0.05). In addition, hearts from diabetic animals had fewer arrhythmias (P < 0.01) and lower left ventricular end-diastolic pressure during reperfusion (P < 0.05). Higher catalase and heme oxygenase-1 content was found in the aorta and myocardium from diabetic rats (P < 0.01). In aortas from diabetic animals, acetylcholine-induced vasodilatation was enhanced and was approximately 15% after inhibition of nitric oxide synthase, compared with 0% in controls. The 15% relaxation was abrogated by heme oxygenase blockade. Mitochondria from the myocardium of diabetic rats showed significant increases in both size and number (P < 0.05). 4. Hearts of long-term Type 1 diabetic rats demonstrated improved recovery of postischaemic cardiac function and reduced reperfusion arrhythmia. Hyperglycaemia may enhance cardiovascular anti-oxidant capacity and mitochondrial neogenesis, which renders the heart resistant to ischaemia and oxidative injury.

Peroxisome proliferator-activated receptor-gamma agonists attenuate angiotensin II-induced collagen type I expression in adventitial fibroblasts.

1. Angiotensin (Ang) II-mediated oxidative stress may be important in enhanced adventitial fibroblast collagen formation. The aim of the present study was to test whether PPAR-gamma agonists 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ2) and pioglitazone could alter AngII-induced collagen type I formation in vascular adventitial fibroblasts via reactive oxygen species (ROS). 2. Vascular adventitial fibroblasts were isolated from rat thoracic aortas of male Sprague-Dawley rats and treated with different concentrations of AngII for different periods of time. The expression of collagen type I induced by AngII was examined by western blot. Expression of PPAR-gamma mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR). Intracellular ROS generation was measured by flow cytometry. Activation of transcription factors nuclear factor (NF)-kappaB and activator protein (AP)-1 was assessed by an electrophoretic mobility shift assay. 3. Angiotensin II increased expression of collagen type I in a time- and dose-dependent manner in adventitial fibroblasts. In addition, AngII stimulated intracellular generation of ROS in adventitial fibroblasts. Pretreatment of cells with 15d-PGJ2 and pioglitazone attenuated collagen type I expression and generation of ROS induced by AngII, respectively. Moreover, we observed that N-acetylcysteine inhibited collagen type I expression induced by AngII as did the PPAR-gamma agonists. Angiotensin II treatment activated the redox-sensitive transcription factors NF-kappaB and AP-1, whereas pretreatment with 15d-PGJ2 and pioglitazone reduced the AngII-induced DNA-binding activity of NF-kappaB but not AP-1. 4 Our data demonstrate that the PPAR-gamma agonists 15d-PGJ2 and pioglitazone attenuate AngII-mediated collagen type I expression in adventitial fibroblasts, which may be mediated by the modulation of ROS release and the redox-sensitive transcription factor NF-kappaB.

Detection of recent HIV-1 infections among men who have sex with men in Beijing during 2005 - 2006 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Men who have sex with men (MSM) have become one of the most risky populations for HIV infection in China. Though several cross-sectional sero-prevalence studies have been conducted, the annual HIV incidence remains unknown in this population.</p><p><b>METHODS</b>We applied IgG-capture BED-enzyme immunoassay (BED-CEIA) to define the recent HIV-1 infections among MSM in Beijing in the years 2005 and 2006 and the annual HIV incidence was estimated.</p><p><b>RESULTS</b>Overall, 1067 MSM samples were collected, including 526 samples in the year 2005 and 541 in 2006. In 2005, of 17 HIV seropositive samples, 7 were identified as recent HIV-1 infections and the estimated HIV infection incidence was 2.9% per year (95% CI, 0.8% - 5.0%). In 2006, of 26 HIV seropositive samples, 9 were identified as recent HIV-1 infections and the estimated annual incidence was 3.6% (95% CI, 1.3% - 5.9%), which was 0.7% higher than that in 2005. Individuals engaging in male group sexual intercourse (5.17% vs 0.87%, P = 0.019) and having receptive anal sexual intercourse more than five times (2.79% vs 0.33%, P = 0.047) in the past 6 months significantly increase the risk of being infected by HIV-1.</p><p><b>CONCLUSIONS</b>A high level of annual HIV-1 infection incidence was observed among MSM in Beijing for the consecutive years 2005 and 2006 with a continuous increasing trend. The rising incidence and related high risk behavior among MSM alarmed the health authorities and calls for more effective intervention strategies among this population.</p>

Paradoxically enhanced heart tolerance to ischaemia in type 1 diabetes and role of increased osmolarity.

There is considerable controversy regarding the tolerance of diabetic hearts to ischaemia and the underlying mechanisms responsible for the increased heart tolerance to ischamia remain uncertain. In the present study, we observed, in vitro, type 1 diabetic heart responses to ischaemia and reperfusion at different degrees of hyperglycaemia. In addition, the possible role of increased osmolarity in cardioprotection due to hyperglycaemia was evaluated. Hearts from 3 week streptozocin-induced diabetic rats were isolated and perfused in a Langendorff apparatus and subjected to 30 min ischaemia and 30 min reperfusion. Cardiac function and the electrocardiogram were recorded. Myocardial content of osmolarity associated heat shock protein (hsp) 90, heme oxygenase (HO)-1 and anti-oxidant enzymes were determined in diabetic or hyperosmotic solution-perfused hearts using western blot. The hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG; 2 x 10(-7) mol/L) or the nitric oxide synthase (NOS) inhibitor Nomega-nitro-L-arginine methyl ester (1 x 10(-5) mol/L) was added to the perfusate to observe the effects of hsp90 inhibition and hsp90-associated endothelial NOS on ischaemic responses of diabetic hearts. Compared with normal control rats, diabetic hearts with severe hyperglycaemia (blood glucose > 20 mmol/L) showed markedly improved postischaemic heart function with fewer reperfusion arrhythmias. Mild hyperglycaemia (< 12 mmol/L) exhibited no significant cardioprotection. Elevated expression of hsp90 accompanied the enhanced resistance to ischaemia in diabetic hearts, which was abrogated by 17-AAG. In the presence of the NOS inhibitor, heart function was preserved, whereas reperfusion arrhythmias were increased in diabetes. Diabetic hearts also had markedly elevated HO-1 and catalase, with no significant change in superoxide dismutase. Hyperosmotic perfusion with glucose or mannitol also increased myocardial hsp90 and catalase. The present findings reveal that heart resistance to ischaemia is increased in short-term type 1 diabetes with severe hyperglycaemia. Elevated osmolarity caused by significant hyperglycaemia may contribute to the enhanced myocardial activity against oxidative injury during ischaemia and reperfusion.

Gene profile for differentiation of vascular adventitial myofibroblasts.

Our previous study demonstrated that TGF-beta1 could induce the differentiation of vascular adventitial fibroblasts (AFs) to myofibroblasts (MFs). The aim of this study was to identify the genes which might be responsible for the cell phenotypic change using genechips. Cultured rat AFs were treated with TGF-beta1 (10 ng/ml) for 0 min, 5 min, 15 min, 2 h, 12 h and 24 h, respectively. Then the cells were gathered to prepare total RNA. We examined TGF-beta1-induced gene expression profiling using Affymetrix oligonucleotide microarrays and analyzed data by GCOS1.2 software. Moreover, expressional similarity was measured by hierarchical clustering. Some of genechip results were confirmed by real-time quantitative RT-PCR. Microarray analysis identified 2121 genes with a 2-fold change or above after TGF-beta1 stimulation. 1318 genes showed a greater than 2-fold increase and 761 genes were reduced 2 folds or more at mRNA levels, whereas a small portion of the total regulated genes (42 genes) displayed dynamically up- and down-regulated pattern. Genes were further segregated for early (peak at 5 min, 15 min and/or 2 h), late (peak at 12 h and/or 24 h), and sustained (2-fold change or above at five time points) temporal response groups according to the time of their peak expression level. Among 1318 up-regulated genes, 333 genes (25.3%) responded rapidly to TGF-beta1 and 159 genes (12.1%) responded in a sustained manner. Most genes (826, 62.6%) were regulated at 12 h or later. For the 761 down-regulated genes, numbers of early and late responsive genes were 335 (44%) and 267 (36.1%), respectively. There were also 159 genes, 19.9% of total down-regulated genes, decreased at five time points treated by TGF-beta1. The results suggested that the gene expressions of secreted phosphoprotein 1 (APP1) and Rho-associated coiled-coil forming kinase 2 (ROCK2) had the same trends as alpha-smooth muscle-actin, a marker of MF differentiation. In addition, the gene expression of potassium voltage-gated channel, Shal-related family and member 2 (KCND2) was up-regulated. Furthermore, it was found that endothelin 1 (EDN1), some complement components, NADPH oxidase 4 (NOX4) and NAD(P)H dehydrogenase, quinone 1 (NQO1) might be involved in MF differentiation. Using microarrary technique, we confirmed some genes that have been identified by other techniques were implicated in MF differentiation and observed new genes involved in this process. Our results suggest that gene expression profiling study is helpful in identifying genes and pathways potentially involved in cell differentiation.

Increased migration of vascular adventitial fibroblasts from spontaneously hypertensive rats.

Experimental evidence has suggested that vascular adventitial fibroblasts (AFs) may migrate into the neointima of arteries after balloon injury in various animal models. However, the research on migration of AFs has been limited to the effects of acute vascular injury. The role of AFs in chronic vascular injury and hypertension is not yet known. In this study, the migration of spontaneously hypertensive rat (SHR)-AFs and Wistar-Kyoto rat (WKY)-AFs from the thoracic aorta was determined by a transwell technique. Our results showed that fetal calf serum, angiotensin II (Ang II), phorbol ester, basic fibroblast growth factor and platelet-derived growth factor-BB induced migration in a dose-dependent manner, and the migration of SHR-AFs was always greater than that of WKY-AFs. Ang II-induced migration of AFs was considered to have been mediated by Ang II type 1 receptor (AT1-R), because the AT1-R antagonist losartan (10(-7)-10(-5) mol/l) suppressed Ang II-induced migration. Ang II-induced migration was also blocked by the extracellular-regulated protein kinase 1/2 (ERK1/2) inhibitor PD98059 (10(-5) mol/l) and p38 kinase inhibitor SB202190 (10(-5) mol/l), indicating that ERK1/2 and p38 kinase were involved in Ang II-induced migration. Ang II (10(-7) mol/l)-induced ERK1/2 and p38 kinase phosphorylation, both of which peaked after 5 min, were suppressed by PD98059 and SB202190, respectively. The Ang-II induced phosphorylation of both proteins was suppressed by losartan, whereas no effect was observed with PD123319, a specific inhibitor of Ang II type 2 receptor (AT2-R). Thus, in the present study, various factors stimulated the migration of SHR-AFs and, to a leber extent, WKY-AFs from the thoracic aorta, and the ERK1/2 and p38 kinase pathways are involved in Ang II-stimulated migration of fibroblasts.

NAD(P)H oxidase-derived reactive oxygen species regulate angiotensin-II induced adventitial fibroblast phenotypic differentiation.

Phenotypic differentiation of adventitial fibroblasts into myofibroblasts is an essential feature of vascular remodeling. The present study was undertaken to test the hypothesis that reactive oxygen species (ROS) are involved in rat adventitial fibroblast differentiation to myofibroblast. Activation of alpha-smooth muscle actin (alpha-SMA) was used as a marker of myofibroblast. Angiotensin II increased intracellular ROS in adventitial fibroblasts that was completely inhibited by the free radical scavenger NAC, the NAD(P)H oxidase inhibitor DPI, and transfection of antisense gp91phox oligonucleotides. Myofibroblast differentiation was prevented by inhibition of ROS generation with DPI, NAC, and antisense gp91phox as shown by decreased expression of alpha-SMA. Angiotensin II rapidly induced phosphorylation of p38 MAPK and JNK, both of which were inhibited by DPI, NAC, antisense gp91phox, and the selective AT1 receptor antagonist, losartan. Inhibiting p38MAPK with SB202190 or JNK with SP600125 also reduced angiotensin II-induced alpha-SMA expression. These findings demonstrate that angiotensin II induces adventitial fibroblast differentiation to myofibroblast via a pathway that involves NADPH oxidase generation of ROS and activation of p38MAPK and JNK pathways.