Sevoflurane anesthesia reduces the expression of inflammatory response genes and ß-site amyloid precursor protein-cleaving enzyme in hippocampi of diabetic mice.

Diabetes and inhaled anesthesia are associated with an increased likelihood of developing postoperative cognitive dysfunction in humans and animal models, but the mechanisms are unclear. This study aimed to investigate the effect and mechanism of sevoflurane anesthesia on cognitive function in diabetic (DM) mice. Spontaneously diabetic db/db and control db/m mice were subject to sevoflurane anesthesia or allowed to breathe air, respectively. The Morris water maze test as spatial learning and novel object recognition test as recognition memory were performed. The expression of inflammatory cytokines and neurotoxicity-related genes in the hippocampus of four groups was measured using real-time PCR. The expression level of neurotoxicity and neuroprotection-related proteins in DM mice hippocampus were estimated using Western blot assay. It is found that DM mice developed cognitive impairment; however, the cognitive impairment was not exacerbated in sevoflurane-exposed mice. Sevoflurane anesthesia led to a decrease in mRNA levels of inflammatory cytokines in DM mice hippocampi, including interleukin 17 (IL-17), C-C motif chemokine (CCL20), CCL7 as well as high mobility group box 1 and beta-site amyloid-ß cleaving enzyme 1; and no effect was observed on the expression of neurotoxicity genes, including amyloid precursor protein, choline O-acetyltransferase, tumor necrosis factor, alpha-induced protein 1, B-cell lymphoma 2 and estrogen receptor 2. In addition, we observed elevated phosphorylation of cAMP response element-binding protein in DM mice exposed to sevoflurane anesthesia. In conclusion, sevoflurane did not exacerbate DM-associated cognitive impairment.

Expression of prostaglandin E2 and EP receptors in human papillary thyroid carcinoma.

The objective of the present study is to determine the role of prostaglandin E2 (PGE2) and downstream EP receptors in the development of human papillary thyroid carcinoma (PTC). A total of 90 thyroid specimens excised from patients undergoing total or subtotal thyroidectomy in the Department of General Surgery, the Fifth Affiliated Hospital of Sun Yat-sen University, China, from August 2013 to September 2014, were analyzed. The quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemical analyses were employed to examine the messenger RNA (mRNA) and protein expression, respectively. The expressions and significances of cyclooxygenase-2 (COX-2), microsomal prostaglandin E synthase-1 (mPGES-1), PGE2, and EP receptors in PTC and nodular goiter were investigated. The COX-2 mRNA and protein expression level significantly increased in the PTC tissues than in the paired noncarcinoma tissues adjacent to the PTC or nodular goiter tissues. The mPGES-1 protein expression was also significantly upregulated in the PTC tissues. All the four subtypes of EP receptors (EP1-4) could express in the thyroid tissues, while only the EP4 mRNA and protein levels significantly increased in the PTC tissues. The local production of PGE2 had a higher-level expression in the PTC tissues than in the noncarcinoma thyroid tissues adjacent to the PTC lesion and the benign nodular goiter tissues. The induction of PGE2 biosynthesis as well as the overexpression of EP4 in PTC suggested that this pathway might play an important role in the carcinogenesis and progression of PTC. These observations raise the possibility that pharmacological inhibition of mPGES-1 and/or EP4 may hold therapeutic promise in this common cancer.

Expression and distribution of Src in the nucleus of myocytes in cardiac hypertrophy.

The Src kinase is involved in signaling events leading to cardiac hypertrophy. The exact effects of tyrosine phosphorylation and subnuclear distribution on cardiac hypertrophy and failure remain to be investigated. In this study, we examined the intranuclear expression and distribution of c-Src, Src phosphorylated at tyrosine 529 (Src[pY529]), Src phosphorylated at tyrosine 418 (Src[pY418]) and Src phosphorylated at tyrosine 215 (Src[pY215]) in the myocardial nuclei of the left ventricle (LV) from 2-, 6-, 12- and 18-month-old spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) rats as normotensive controls by western blot analysis, immunofluorescent labeling and immunoprecipitation. Cellular Src (c-Src) expression in the myocardial nuclei of the LV of the 2-, 6-, 12- and 18-month-old SHHF rats was not significantly different from that in the myocardial nuclei of the LV of the age-matched WKY rats. Although there were no significant differences observed between the levels of Src[pY529] and Src[pY418] in the myocardial nuclei of the LV of the 2-month-old SHHF and WKY rats, the expression of Src[pY529] significantly decreased, while that of Src[pY418] significantly increased in the myocardial nuclei of the LV of the 6-, 12- and 18-month-old SHHF rats compared to the age-matched WKY controls. Furthermore, as demonstrated by double labeling with antibodies against fibrillarin and Src-associated in mitosis 68 kDa (Sam68), c-Src was co-localized with both Sam68 and fibrillarin in the nuclei; Src[pY529] co-localized with fibrillarin, but Src[pY418] co-localized with Sam68. The results from the present study suggest that the dephosphorylation of Src tyrosine kinase 529, the phosphorylation of tyrosine 418 and their subnuclear redistribution are involved in endonuclear signal transduction in cardiac myocytes, which regulates the development and progression of LV eccentric hypertrophy induced by hypertension.

Expression and redistribution of ß-catenin in the cardiac myocytes of left ventricle of spontaneously hypertensive rat.

Beta-catenin is not only an adhering junction protein, but also the central player of the canonical Wnt signalling pathway. In order to investigate the roles of ß-catenin in the mechanism of myocardial hypertrophy, we determined the expression and distribution of ß-catenin in the cardiomyocytes of spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) rats. We identified the reducing of ß-catenin expression in the membrane protein fraction but increasing in the nuclear protein in the 6 and 12 month-old SHHF rats as compared with the age-matched WKY rats by Western blotting. Immunolabeling of ß-catenin colocalized with cadherin at the intercalated disc sites and showed nuclear accumulation in myocytes of SHHF rats. We also revealed that the association between glycogen synthase kinase-3ß and ß-catenin had weakened in the 6 month-old SHHF rats as compared with the age-matched WKY rats by immunoprecipitation. These findings suggested that nuclear translocation of ß-catenin might play important roles in regulating signal transduction in the decompensated hypertrophy stage.

[Correlation of early phase contrast enhancement of multi-detector row computed tomography to tumor stroma of nodular solid lung adenocarcinoma].

BACKGROUND & OBJECTIVE: Dynamic enhanced multi-detector row CT (MDCT) has been used in differential diagnosis of pulmonary nodules, but its mechanism was unclear yet. This study was to evaluate the correlations of early phase enhancement of MDCT to proportion and distribution of stroma in solid lung adenocarcinoma. METHODS: A total of 31 patients with lung adenocarcinoma underwent routine contrast-enhanced MDCT. All lesions were solid solitary pulmonary nodules confirmed by pathology. CT observation items included net enhancement and distribution of enhancement. Tumor morphology was observed with HE staining. About 25 fields of view of each specimen at low magnification were scanned to obtain digital data. Semi-auto segmentation software was used to calculate mean stroma proportion. RESULTS: The proportion of invasive stroma in tumors was correlated positively to CT enhancement value (r=0.483, P=0.006). Of the 31 nodules, 18 (58.1%) showed homogenous enhancement, 10 (32.3%) showed peripheral inhomogenous enhancement, 1 (3.2%) showed central inhomogenous enhancement, 1 (3.2%) showed asymmetrical inhomogenous enhancement, 1 (3.2%) showed no enhancement; 18 (58.1%) nodules showed mixed distribution of stroma, 11 (35.5%) showed peripheral distribution, 1 (3.2%) showed central distribution, 1 (3.2%) showed asymmetrical distribution. Most acinar adenocarcinomas had net enhancement of > 20 Hu, which was significantly higher than that of solid adenocarcinomas with mucin subtype (P=0.005). CONCLUSIONS: Extent and pattern of CT enhancement of solid lung adenocarcinoma nodules reflect the proliferation and distribution of stroma, respectively. It is helpful to comprehend some false negative on CT enhancement by adequately understanding of the pathologic features of different subtypes of lung adenocarcinoma.

[Phosphorylation and nuclear translocation of serine 722 and serine 910 of focal adhesion kinase in hypertrophic cardiac myocytes of left ventricle of spontaneously hypertensive rats].

OBJECTIVE: To investigate the role of focal adhesion kinase (FAK) in cardiac hypertrophy induced by hypertension. METHODS: Using immunofluorescent labeling, confocal microscopy and Western blot, the expression and subcellular location of FAK-pSer722 and FAK-pSer910 were determined in cardiac myocytes of the left ventricles from 2, 6, 12, and 18 month-old spontaneously hypertensive heart failure (SHHF) rats and age-matched Wistar-Kyoto (WKY) control rats, respectively. RESULTS: There was no obvious difference in FAK-pSer722 and FAK-pSer910 expression between 2 month-old SHHF and WKY rats. In contrast with the control groups, the expression of FAK-pSer722 and FAK-pSer910 significantly increased in cardiac myocytes of the left ventricle, from 6, 12 and 18 month-old SHHF rats. Both FAK-pSer722 and FAK-pSer910 were translocated and acummulated in nuclei of cardiac myocytes from 6, 12, and 18 month-old SHHF rats. CONCLUSION: Phosphorylation and translocation of serine 722 and serine 910 of phosphorylated FAK play an important role in the de-compensatory cardiac hypertrophy.

Cardiac-specific haploinsufficiency of beta-catenin attenuates cardiac hypertrophy but enhances fetal gene expression in response to aortic constriction.

In addition to its role in cell adhesion, beta-catenin is an important signaling molecule in the Wnt/Wingless signaling pathway. Recent studies have indicated that beta-catenin is stabilized by hypertrophic stimuli and may regulate cardiac hypertrophic responses. To explore the role and requirement of beta-catenin in cardiac development and hypertrophy, we deleted the beta-catenin gene specifically in cardiac myocytes by crossing loxP-floxed beta-catenin mice with transgenic mice expressing a Cre recombinase under the control of the alpha-myosin heavy chain promoter. No homozygous beta-catenin-deleted mice were born alive and died before embryonic day 14.5, indicating significant and irreplaceable roles of beta-catenin in embryonic heart development. Heterozygous beta-catenin-deleted mice, however, demonstrated no structural and functional abnormality. The response of heterozygous beta-catenin-deleted mice to transverse aortic constriction, however, was significantly attenuated with decreased heart weight and heart weight/body weight ratio compared to controls with intact beta-catenin genes. Hemodynamic analysis revealed that there was no difference in cardiac function between wild-type and heterozygous beta-catenin-deleted mice. On the other hand, the expression of fetal genes, beta-myosin heavy chain, atrial and brain natriuretic peptides was significantly higher in heterozygous beta-catenin-deleted mice when compared to wild-type beta-catenin mice. These results suggest that the cytoplasmic level of beta-catenin modulates hypertrophic response and fetal gene reprogramming after pressure overload.

[Expression of focal adhesion kinase in cardiac myocytes of hypertrophic ventricle].

OBJECTIVES: To investigate the role of focal adhesion kinase (FAK) in the pathogenesis of cardiac hypertrophy induced by hypertension. METHODS: Using immunofluorescent labeling, confocal microscopy and Western blotting, the expression and subcellular localization of FAK in the cardiac myocytes of left ventricle were determined in 2, 6, 12, and 18 month-old rats with spontaneously hypertensive heart failure (SHHF) along with age-matched control Wistar-Kyoto (WKY) rats. RESULTS: There was no significant difference of FAK expression between 2 month-old SHHF and WKY rats (50.5+/-6.9 vs. 49.8+/-5.0, n=6, P>0.05). In contrast with the control groups, the expression of FAK significantly increased in 6, 12 and 18 month-old SHHF rats (130.6+/-3.0 vs. 47.3+/-1.3, 144.7+/-5.4 vs. 46.4+/-3.1, 141.4+/-9.8 vs. 48.5+/-2.2, each groups n=6, P<0.05) with FAK protein primarily cumulated in the intercalated disks and nuclei. CONCLUSIONS: FAK may play a role in the cell signaling transduction leading to cardiac hypertrophy, presumably through regulations of hypertrophic gene transcription and RNA processing.

Upregulation of gamma-catenin compensates for the loss of beta-catenin in adult cardiomyocytes.

Recent progresses in signal transduction have revealed that beta-catenin signaling controls embryonic development, tumorigenesis, cell shape, and polarity. The role of this pathway in myocyte shape regulation during cardiac hypertrophy and failure is, however, not clearly defined. Since homozygous knockout of beta-catenin is embryonically lethal, we have deleted beta-catenin genes specifically in the heart of adult mice by crossing loxP-flanked beta-catenin mice with transgenic mice expressing tamoxifen-activated MerCreMer protein (MCM) driven by the alpha-myosin heavy chain promoter. Administration of tamoxifen to homozygous loxP-flanked beta-catenin mice positive for MCM induces the deletion of beta-catenin only in cardiomyocytes. Immunolabeling with beta-catenin antibody demonstrates that 90% of cardiomyocytes completely lose their beta-catenin expression but maintain normal rod-shaped morphology. The intercalated disk of cardiomyocytes lacking beta-catenin is morphologically unremarkable with normal distribution of vinculin, N-cadherin, desmoplakin, ZO-1, connexin43, and alpha-, gamma-, and p120 catenins. The expression level of these proteins, except that of gamma-catenin, is also similar in tamoxifen-treated and control mice with both homozygous loxP-flanked beta-catenin genes and the MCM transgene. Western blot analyses reveal that gamma-catenin increases in the heart of beta-catenin knockout mice compared with controls. Confocal microscopy also demonstrates that gamma-catenin has significantly increased in the intercalated disk of cardiomyocytes lacking beta-catenin. Echocardiographic data indicate that the knockout mice maintain normal ventricular geometry and cardiac function. The results suggest that upregulation of gamma-catenin can compensate for the loss of beta-catenin in cardiomyocytes to maintain normal cardiac structure and function.

Sonographic appearance of a testicular yolk sac tumor in a 2-year-old boy.

Yolk sac tumor (YST) of testis is the most common of all childhood testicular malignancies. We report a case of testicular YST in a 2-year-old boy. The tumor appeared sonographically as an ovoid, homogeneous, well-circumscribed, isoechoic, solid testicular mass with good sound-through transmission and increased internal vascularity on color Doppler imaging. The serum alpha-fetoprotein level was 4,396 ng/ml. Pathological examination confirmed YST at at stage I. Although the sonographic appearance of YST of the testis is nonspecific, the diagnosis is achievable in clinical practice on the combination of elevated serum alpha-fetoprotein level and sonograms depicting a solid testicular hypervascular mass.

Nuclear compartmentalization of FAK and FRNK in cardiac myocytes.

Focal adhesion kinase (FAK) and FAK-related non-kinase (FRNK) accumulate in the nucleus of cardiac myocytes during hypertensive hypertrophy. Nuclear FAK and FRNK are phosphorylated on different serines and form distinct bright spots. The subnuclear distribution of serine-phosphorylated FAK and FRNK was examined in this study by double labeling with fibrillarin, a component of nucleoli, and Sam68, a constituent of Sam68 nuclear bodies. We also investigated the role of protein kinase C (PKC)-mediated phosphorylation of FAK and FRNK on nuclear translocation. PKC activation by 12-O-tetradecanoylphorbol 13-acetate treatment increased serine phosphorylation of FAK and FRNK. Specifically, FAK was phosphorylated on serine 722 but not serine 910. On the other hand, FRNK was phosphorylated on serine 217, the equivalent site of FAK serine 910, but not serine 30, the homologous site of FAK serine 722. Serine-phosphorylated FAK and FRNK redistributed into the nucleus and formed distinct patterns. FAK with phosphorylation on serine 722 colocalized with Sam68 but not fibrillarin. On the contrary, FRNK phosphorylated on 217 coexisted with fibrillarin but not Sam68. Immunoprecipitation also confirmed that FAK associated with Sam68 and FRNK interacted with fibrillarin, respectively. These results suggest that FAK and FRNK target different nuclear subdomains by their association with distinct nuclear proteins.

Myocardial expression and redistribution of GRKs in hypertensive hypertrophy and failure.

G-protein-coupled receptor kinases (GRKs) are involved in cardiac hypertrophy and failure. But their temporal expression and cellular localization during the development of hypertrophy and its transition to failure remains to be investigated. In this study, we determined the expression and subcellular distribution of GRK2, GRK3, GRK5, and GRK6 in cardiac myocytes of 2- to 24-month-old spontaneously hypertensive heart failure (SHHF) rats. GRK2 increased in the intercalated disks in 6-, 12-, and 24-month-old SHHF rats, although total expression remained relatively constant from 2 to 24 months in both SHHF and normotensive rats. GRK3 expression progressively increased in 6-, 12-, and 24-month-old SHHF rats and was significantly higher than in age-matched controls. Immunolabeling of GRK3 showed a typical pattern of cross-striations that colocalized with alpha-actinin and G(alphas) at Z-lines in both SHHF and control rats. GRK5 expression showed no change from 2 to 24 months in both SHHF and normotensive rats. Confocal analysis revealed nuclear translocation of GRK5 in myocytes of SHHF rats. GRK6 had a striated pattern colocalized with alpha-actinin at Z-lines in the cytoplasm and was also present in the intercalated disks of cardiac myocytes from both SHHF and control rats. GRK6 expression increased in 12- and 24-month-old SHHF rats and was significantly higher than in age-matched controls. GRK6 labeling was reduced at the intercalated disks, but increased in the cytoplasm of cardiac myocytes from SHHF rats compared to age-matched controls. The increased expression of GRK3 and GRK6 and subcellular redistribution of GRK2, GRK5, and GRK6 in SHHF rats may be involved in abnormal remodeling of cardiac myocytes in hypertensive hypertrophy and failure.

Structural basis of ventricular remodeling: role of the myocyte.

Structural remodeling plays a major role in the progression of various heart diseases to congestive heart failure (CHF). Major contributors to this remodeling process in the heart include alterations in myocyte shape, myocyte number, and extracellular matrix. However, it is unclear as to which of these changes is most critical in the development of CHF, and this may vary by etiology. Myocyte shape alterations largely underlie the increase in chamber diameter/wall thickness characteristic of CHF. This review mainly focuses on the role of myocyte shape in ventricular remodeling. Several signaling molecules have been implicated in this process. As we learn more about the components of myocardial remodeling, new strategies to combat the progression of heart disease should arise.

Subcellular redistribution of focal adhesion kinase and its related nonkinase in hypertrophic myocardium.

Focal adhesion kinase (FAK) and focal adhesion kinase-related nonkinase (FRNK) are likely involved in mechanical signaling during hypertension. We investigated expression, subcellular distribution, and phosphorylation of FAK, as well as FRNK in left ventricles of spontaneously hypertensive heart failure rats. Compared with normotensive controls, FAK and FRNK increased in left ventricles of hypertensive rats. Increased FAK and FRNK were mainly present in membrane cytoskeleton and nuclear fractions. Confocal microscopy demonstrated that FAK and FRNK translocated to nuclei and intercalated disks in cardiac myocytes from hypertensive rats. Serine and tyrosine phosphorylation of FAK increased dramatically in hypertensive rats. FAK phosphorylated at tyrosine 397 was present in membranes and intercalated disks, but not in nuclei. FAK was also phosphorylated on serine 722 but not on serine 910. In contrast, FRNK was phosphorylated on serine 217, the equivalent site of FAK serine 910, but not serine on 30, the homologous site of FAK serine 722. Serine phosphorylated FAK and FRNK accumulated in membranes and nuclei but not in intercalated disks. Nuclear translocation of FAK and FRNK may play important roles in regulating mechanical signal transduction in cardiac myocytes.

Myocyte redistribution of GRK2 and GRK5 in hypertensive, heart-failure-prone rats.

Gprotein-coupled receptor kinases (GRKs) are known to be involved in the development of cardiac hypertrophy. Their exact role and subcellular distribution during cardiac hypertrophy and failure remain to be elucidated. We examined expression and subcellular distribution of GRK2 and GRK5 in the left ventricle of female spontaneously hypertensive heart failure (SHHF) rats at 6 months of age using Western blots and fluorescent confocal microscopy. GRK2 was expressed mainly in the Triton X-100 soluble fraction in the left ventricle with similar expression levels between SHHF and age-matched Wistar-Kyoto (WKY) rats. GRK2 had a striated pattern which colocalized with sarcomeric alpha-actinin and G protein in both SHHF and WKY rat myocytes and specifically accumulated in the intercalated disks of myocytes from SHHF but not WKY rats. GRK5 was expressed in both the Triton X-100 soluble fraction and Triton X-100 insoluble fraction in the left ventricle with similar expression levels between SHHF and WKY rats. GRK5 distributed diffusely in the cytoplasm in both SHHF and WKY rat myocytes and specifically accumulated in the nucleus of myocytes from SHHF but not WKY rats. GRK5 colocalized with coilin, the major component of the nuclear substructure involved in RNA synthesis and processing. The results suggest different roles for GRK2 and GRK5 in G-protein signaling and RNA biogenesis. Subcellular redistribution of GRK2 and GRK5 may be involved in cardiac hypertrophy resulting from chronic hypertension.