ABHD2 deficiency aggravates ovalbumin-induced airway remodeling through the PI3K/Akt pathway in an animal model of chronic asthma

Airway remodeling is a major pathological characteristic of chronic obstructive pulmonary disease (COPD). This study aimed to investigate the effect of Abhd2 deficiency on ovalbumin (OVA)-induced airway remodeling and inflammation in vivo. Abhd2-deficient mice were used to establish an OVA-induced asthma model. Lung tissues were analyzed using hematoxylin and eosin (HE) staining, Masson staining, immunohistochemistry, quantitative reverse transcription- polymerase chain reaction (qRT-PCR), and western blotting were used to determine the role of Abhd2 in the regulation of OVA-induced airway remodeling and inflammation. Our findings revealed that the RNA expression of inflammatory factors, including IL-1β, IL-6, IL-4, and IL-13, was significantly increased in OVA-induced Abhd2 Gt/Gt asthmatic mice. The expression of IFN-γ was decreased significantly in OVA-induced Abhd2 Gt/Gt asthmatic mice. The protein expression of airway remodeling factors, including α-SMA, type I collagen, and Ki67, was also increased in OVA-induced Abhd2 Gt/Gt asthmatic mice compared to that in OVA-induced wild-type (WT) mice. Additionally, Abhd2 deficiency promoted the expression of p-Akt in tissues of the asthma model. These results suggest that Abhd2 deficiency exacerbates airway remodeling and inflammation through the PI3K/Akt pathway in chronic asthma.

Reactive cutaneous capillary endothelial proliferation predicted the efficacy of camrelizumab in patients with recurrent/metastatic head and neck squamous cell carcinoma

BACKGROUND

Reactive cutaneous capillary endothelial proliferation (RCCEP), a special adverse event (AE) only observed in patients treated with camrelizumab, was reported to be correlated with the efficacy of camrelizumab in patients with advanced hepatocellular carcinoma. This study to analyze the possible correlation between the occurrence of RCCEP and efficacy of camrelizumab in patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC).

MATERIAL AND METHODS

In this study, we retrospectively analyzed the efficacy and RCCEP occurrence of camrelizumab in 58 patients with R/M HNSCC in the Shanghai Ninth People's Hospital affiliated to Shanghai JiaoTong University School of Medicine between January 2019 and June 2022. Kaplan-Meier analysis was used to assess the correlation between the occurrence of RCCEP and the survival of enrolled patients, and COX multifactor analysis was adopted to evaluate associated factors that affected the efficacy of camrelizumab immunotherapy.

RESULTS

A significant correlation between the incidence of RCCEP and a higher objective response rate was observed in this study (p=0.008). The occurrence of RCCEP was associated with better median overall survival (17.0 months vs. 8.7 months, p<0.0001, HR=5.944, 95% CI:2.097-16.84) and better median progression-free survival (15.1 months vs. 4.0 months, p<0.0001, HR=4.329,95% CI:1.683-11.13). In COX multifactor analysis, RCCEP occurrence was also an independent prognostic factor affecting OS and PFS in patients with R/M HNSCC.

CONCLUSIONS

The occurrence of RCCEP can show a better prognosis, it could be used as a clinical biomarker to predict the efficacy of camrelizumab treatment.

Identification of Hub Genes Associated with Gastric Cancer via Bioinformatics Analysis and Validation Studies

Introduction

Hub genes related to the development of gastric cancer (GC) were identified based on bioinformatics methods. This study aimed to identify GC hub genes, explore the expression of genes in GC and their correlation with prognosis, so as to provide strategies for GC diagnosis and targeted therapy.

Methods

Two messenger RNA (mRNA) microarray datasets were downloaded from GEO database. These data were combined with TCGA database to obtain common DEGs between GC tissues and normal tissues. GO and KEGG pathway enrichment analysis was performed. Visualized PPI network analysis was performed by Cytoscape to further identify hub genes. GEPIA database was used to evaluate the prognostic value of hub genes. The online software Ualcan was applied to analyze the expression of the prognosis-related genes in cancer tissues and normal tissues from different perspectives of primary GC, TNM stage, nodal metastasis status and tumor grade. Immunohistochemical staining of GC tissues and normal tissues was performed to evaluate the expression of signature genes in GC.

Results

Eighty-four common differentially expressed genes (DEGs) in GC were identified. These genes were closely related to the P13K-Akt signal pathway and other signaling pathways. Ten hub genes were identified. Collagen type I alpha 1 (COL1A1) and collagen type IV alpha 1 (COL4A1) were significantly associated with poor prognosis of GC and were all positively correlated with T stage, distant metastasis, and TNM stage of GC. Immunohistochemistry revealed that the expression of these 2 genes was upregulated in GC tissues. These 2 genes expression was negatively related with 5-year survival rate of GC patients.

Conclusion

Ten highly expressed hub genes in GC tissue were mined by bioinformatics method. COL1A1 and COL4A1 were significantly associated with the prognosis of GC. This study provided a theoretical basis for the pathogenesis, clinical diagnosis and therapeutic targets of GC.

The prognostic value of splenic abnormalities in pretreatment 18F-FDG PET/CT in patients with complete response diffuse large B-cell lymphoma

AIM

To investigate whether spleen imaging characteristics of baseline 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography (PET)/computed tomography (CT) can help to predict the clinical outcome in complete response (CR) diffuse large B-cell lymphoma (DLBCL).

MATERIALS AND METHODS

Three hundred and six patients with DLBCL were enrolled in the study and divided into recurrence and non-recurrence groups. The splenic abnormalities were compared using the chi-square test and quantitative indexes were compared using the t-test. The Cox proportional hazard regression model was used for univariate and multivariate analysis. Kaplan-Meier curves and log-rank tests were used to compare progression-free survival (PFS). Propensity score matching (PSM) was used to match patients with and without splenic abnormalities according to age, gender, and initial Ann Arbor stage at a 1:2 ratio (52:104); then the recurrence and PFS results were compared again.

RESULTS

Age, international prognostic index (IPI), stage, splenomegaly, and focal splenic lesions were significantly different between the recurrence and non-recurrence groups. IPI, stage, baseline spleen mean standard uptake value (SUVmean)/liver SUVmean, splenomegaly, and focal lesions were selected by Cox single-factor analysis, and only focal lesions showed a statistical difference in terms of Cox multivariate analysis (p=0.022, hazard ratio [HR]: 2.843). After PSM, focal splenic lesions (n=20) were still statistically different (p=0.003) between the recurrence and non-recurrence groups, and this played an essential role in PFS forecasting (p=0.0004, HR: 3.767).

CONCLUSION

Focal splenic lesions were identified as an independent risk factor for the prognosis of DLBCL. Pretreatment splenomegaly and focal splenic lesions appeared to be related to the relapse and PFS of DLBCL patients. Focal splenic lesions still showed meaningful predictive value even with propensity matching.

Association between hsa_circ_0006156 expression and incidence of gastric cancer

OBJECTIVE

To screen the differentially expressed circular ribonucleic acids (circRNAs) related to gastric cancer and to explore their associations with the clinicopathological features of gastric cancer.

PATIENTS AND METHODS

Cancer tissues of 50 gastric cancer patients undergoing surgical resection in our hospital from April 2015 to December 2018 were collected as an experimental group, while the para-carcinoma tissues were used as the control group. First, the differentially expressed circRNAs were screened by analyzing the circRNA profile in the microarray. Then, the expression of hsa_circ_0006156 in tissues was detected via Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR) in both groups. The potential associations of the relative expression level of hsa_circ_0006156 with clinicopathological features and prognosis were analyzed according to the clinical data of gastric cancer patients.

RESULTS

Six significantly downregulated circRNAs in gastric cancer patients were screened out. The results of RT-qPCR showed that the expression level of hsa_circ_0006156 was significantly lower in gastric cancer tissues than that in para-carcinoma tissues (p<0.05). Accordingly, 50 gastric cancer patients were divided into hsa_circ_0006156 high expression group and hsa_circ_0006156 low expression group based on the fold change of hsa_circ_0006156 in para-carcinoma tissues than that of gastric cancer tissues (fold change>3). The expression level of hsa_circ_0006156 was not correlated with the age and gender of gastric cancer patients (p>0.05) but correlated with the lymph node metastasis (p<0.05), nerve invasion (p<0.05), and degree of tumor differentiation (p<0.05). The expression level of hsa_circ_0006156 was also significantly associated with the progression-free survival (PFS) and overall survival (OS) of patients (p<0.05). According to the multivariate analysis of variance, the PFS of gastric cancer patients was associated with nerve invasion, lymph node metastasis, and hsa_circ_0006156 expression (relative risk coefficient=1.742, 2.329, and 3.003). Meanwhile, the OS was associated with lymph node metastasis, nerve invasion, degree of tumor differentiation, and hsa_circ_0006156 expression (relative risk coefficient =1.604, 2.405, 2.114, and 2.004). Moreover, the survival analysis revealed that PFS was markedly prolonged in the hsa_circ_0006156 high expression group compared with that in the hsa_circ_0006156 low expression group.

CONCLUSIONS

The expression of hsa_circ_0006156 substantially declines in gastric cancer tissues, which is related to the differentiation degree, presence, or absence of lymph node metastasis and prognosis of gastric cancer patients. Therefore, hsa_circ_0006156 may clinically serve as a biomarker for the prognostic prediction of gastric cancer patients.

Effects of miR-223 on colorectal cancer cell proliferation and apoptosis through regulating FoxO3a/BIM

OBJECTIVE

Colorectal cancer is a common malignant tumor of the digestive tract. It frequently occurs at the junction of the rectum and sigmoid colon. It is characterized by high mortality and poor prognosis. Bcl-2 interacting mediator of cell death (BIM) plays a role in the regulation of cell proliferation and apoptosis, and involves in the pathogenesis of colorectal cancer. The transcription factor forkhead, transcription factor O subfamily 3a (FoxO3a) plays a role in the regulation of BIM expression and is associated to the pathogenesis of colorectal cancer. Bioinformatics analysis suggests that there is a targeted relationship between FoxO3a and microRNA-223 (miR-223). This study aims to investigate effects of miR-223 on the regulation of FoxO3a/BIM signaling pathway and colorectal cancer cell proliferation and apoptosis.

MATERIALS AND METHODS

Colorectal cancer cell line SW620 and normal colorectal epithelial cell line NCM460 were cultured in vitro. Dual luciferase reporter assay was used to validate the relationship between miR-223 and FoxO3a. Flow cytometry was adopted to detect apoptosis. EdU staining was applied to test cell proliferation. Western blot was selected to determine FoxO3a and BIM protein expressions.

RESULTS

There was targeted regulatory relationship between miR-223 and FoxO3a. MiRa-223 up-regulated, FoxO3a and BIM expressions reduced, and cell proliferation was enhanced in SW620 cells compared with NCM460 cells. MiR-223 inhibitor or pIRES2-FoxO3a transfection significantly increased FoxO3a and BIM expressions, attenuated cell proliferation, and enhanced cell apoptosis.

CONCLUSIONS

MiR-223 targeted inhibited expression of FoxO3. Down-regulating the expression of miR-223, it increased the expressions of FoxO3a and BIM, weakened SW620 cells proliferation and induced apoptosis.

hsa_circ_0092306 Targeting miR-197-3p Promotes Gastric Cancer Development by Regulating PRKCB in MKN-45 Cells

Gastric cancer (GC) is one of the most common cancers worldwide and is thus a global cancer burden. Here, we focused on a novel circular RNA hsa_circ_0092306 and explored the potential molecular mechanism to provide a new target for and novel insights into GC treatment. The GEO microarray was mined and analyzed with R software. Sanger sequencing and RNase R assay were applied to verify the identification of hsa_circ_0092306. Quantitative real-time PCR and western blot were performed to measure the mRNA and protein levels. Pull-down and luciferase reporter assays were conducted to confirm the target relationships. Annexin V-PI apoptosis flow cytometry, 3-(4,5Dimethylthiazol- yl)-2,5Dimethylthiazol-2-yl)-2,5diphenyltetrazolium bromide (MTT), wound healing, and Transwell assays were applied to detect cell apoptosis, viability, migration, and invasion in MKN-45 cells, respectively. A xenograft in vivo experiment was conducted to confirm the cell experiment results. hsa_circ_0092306 was upregulated in GC tissues and GC cells, and promoted GC development in MKN-45 cells. hsa_circ_0092306 inhibited tumor suppressor miR-197-3p expression but promoted tumor promotor protein kinase C beta (PRKCB) expression in MKN-45 cells. hsa_circ_0092306 and PRKCB had a common target (miR-197-3p) and were negatively related to miR-197-3p expression. hsa_circ_0092306 promoted the development of GC by regulating the pathway of miR-197-3p/PRKCB in MKN-45 cells.

Effect of PLK1 inhibition on cisplatin-resistant gastric cancer cells

OBJECTIVE

This study aims to investigate the effect of polo-like kinase 1 (PLK1) inhibition on cisplatin (DDP)-resistant gastric cancer (GC) cells.

METHODS

The transcriptional level of PLK1 was measured by quantitative reverse-transcription polymerase chain reaction. Expressions of PLK1 and its downstream mediators as well as autophagy-related protein LC3 I/LC3 II were detected by western blot. An 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 5-ethynyl-2'-deoxyuridine immunofluorescent staining were conducted to evaluate the cell viability and replication activity separately. Flow cytometry was carried out to determine the cell cycle status. The GFP-LC3 vector contributed toward tracking the formation and aggregation of autophagosomes.

RESULTS

Drug-resistant SGC-7901/DDP cells showed insignificant changes in all phases after DDP treatment, including DNA replication, cell proliferation, cell cycle, and apoptosis, whereas DDP could significantly improve the autophagy level of SGC-7901/DDP as well as PLK1expression. By downregulating the expression of PLK1, both BI2536 andsi-PLK1 enhanced SGC-7901/DDP sensitivity to DDP, suppressing the proliferation and autophagy as well as improving the apoptosis rate. PLK1 inhibition also resulted in the repression of cell division regulators CDC25C and cyclin B1.

CONCLUSION

Together, our experimental results illustrated that the DDP resistance of GC cells might be associated with the aberrant overexpression of PLK1. PLK1 inhibition, including si-PLK1 and BI2536 treatment, could restore the chemosensitivity of drug-resistant SGC-7901/DDP cells and enhance the efficacy of DDP, revealing the potential value of PLK1 inhibition in GC chemotherapy.

Crystal structure of (6,6′-((ethane-1,2-diylbis(azanylylidene))bis(methanylylidene))bis(2-chlorophenolato-κ2N,O))copper(II), C16H12Cl2CuN2O2

C16H12Cl2CuN2O2, orthorhombic, Pbca (no. 61), a = 12.8449(5) Å, b = 12.5266(6) Å, c = 19.0540(11) Å, V = 3065.8(3) Å3, Z = 8, Rgt(F) = 0.0423, wRref(F2) = 0.1164, T = 173(2) K.

The crystal structure of diaqua-2,2′-((cyclohexane-1,2-diylbis(azanylylidene))bis(methanylylidene))diphenolato-κ4 N,N′,O,O′)manganese(III) perchlorate, C20H24MnClN2O4

C20H24MnClN2O4, triclinic, P1̅ (no. 2), a = 7.9912(8) Å, b = 11.8174(9) Å, c = 12.7781(15) Å, α = 112.855(9)°, β = 97.649(9)°, γ = 91.215(7)°, V = 1098.6(2) Å3, Z = 2; R gt(F) = 0.0491, wR ref(F 2) = 0.1319, T = 250(2) K.

Manganese-12 acetate suppresses the migration, invasion, and epithelial-mesenchymal transition by inhibiting Wnt/β-catenin and PI3K/AKT signaling pathways in breast cancer cells

BACKGROUND

Breast cancer is the leading cause of cancer-related death in the world, and it is of great value to reveal the molecular mechanisms of breast cancer progression and develop new therapeutic targets.

METHODS

Transwell assay is used to analyze the migration and invasion of breast cancer cells. Real-time PCR and western blotting assay are applied to detect the expression levels of epithelial-mesenchymal transition markers and the key members of Wnt/β-catenin and PI3K/AKT signaling pathways.

RESULTS

Manganese-12 acetate (Mn12Ac) significantly inhibited the migration and invasion of MCF7 and MDA-MB-231 breast cancer cells. Western blotting assay further showed that Mn12Ac significantly upregulated E-cadherin, and downregulated N-cadherin and vimentin. We further found that Mn12Ac reduced the mRNA expressions of epithelial-mesenchymal transition-associated transcription factors snail, slug, twist1, and ZEB1 using real-time PCR assay. Importantly, we further found that Mn12Ac significantly reduced the Wnt1 and β-catenin protein expressions, and suppressed the phosphorylation of PI3K and AKT in MCF7 and MDA-MB-231 breast cancer cells. Very interestingly, we also showed that Mn12Ac decreased the mRNA and protein expressions of programmed cell death ligand 1.

CONCLUSION

Taken together, our results suggested that Mn12Ac inhibited the migration, invasion, and epithelial-mesenchymal transition by regulating Wnt/β-catenin and PI3K/AKT signaling pathways in breast cancer.

Expression and significance of vWF, GMP-140 and ADAMTS13 in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

The aim of this study was to investigate the role of the von Willebrand factor (vWF) in patients with aneurysmal subarachnoid hemorrhage (aSAH), platelet membrane glycoprotein-140 (GMP-140). The aim is also to discover the expression and clinical significance of von Willebrand factor (vWF) cleaving protease (ADAMTS13).

PATIENTS AND METHODS

83 patients with aSAH were selected from January 2014 to December 2016. The patients were divided into cerebral vasospasm group (CVS group) (n = 37) and no convulsion group (non-CVS group) (n = 46); delayed cerebral ischemia group (DCI group) (n = 31) and non-delayed cerebral ischemia group (non-DCI group) (n = 52). Also, the different aneurysm diameter group included 43 patients in < 5 mm group, 29 patients in 5-10 mm group, 11 patients in > 10 mm group. The number of patients in the good prognosis group and the poor prognosis group were 49 and 34, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of vWF, GMP-140, and ADAMTS13 in plasma of aSAH patients, and the correlation between the indexes was analyzed.

RESULTS

The repeated measures analysis of variance showed that there was no significant difference in plasma vWF, GMP-140, and ADAMTS13 levels in each group of the aSAH patients (p < 0.05). The vWF level of the CVS group was higher than that of the non-CVS group on day 4 and day 10. The GMP-140 level of the CVS group was higher than that of the non-CVS group on day 1, day 4 and day 10. And the ADAMTS13 level was lower than that of the non-CVS group on day 1 and day 10. The difference was statistically significant (p < 0.05). The plasma vWF level of DCI group was higher than that of the non-DCI group on day 1 and day 4. The plasma GMP-140 level at day 4 was higher than that of the non-DCI group. The plasma ADAMTS13 level at day 1 was lower than that in the non-DCI group. The difference was significant (p < 0.05). The plasma vWF level in > 10 mm group was higher than that in < 5 mm group and 5-10 mm group at day 1 and day 4. The plasma vWF level in 5-10 mm group was higher than that in < 5 mm group at day 4. The plasma GMP-140 levels in > 10 mm group were higher than that in < 5 mm group and 5-10 mm group at day 1 and d ay 4. The plasma GMP-140 level in 5-10 mm group was higher than that in < 5 mm group at day 1. The plasma ADAMTS13 level in > 10 mm group was lower than that in < 5 mm group and 5-10 mm group on day 1. Moreover, the plasma ADAMTS13 level in 5-10 mm group was lower than that in < 5 mm group: p < 0.05. The plasma vWF level in the good prognosis group was lower than that in the poor prognosis group on day 4 and day 10. On day 1, day 4, and day 10, the level of GMP-140 was lower than that of the poor prognosis group. The ADAMTS13 level on day 1 and day 4 was higher than that in the poor prognosis group. The difference was statistically significant (p < 0.05). Pearson product moment correlation analysis showed that the plasma vWF level was positively correlated with GMP-140 at day 1 (r = 0.334, p < 0.05), negatively correlated with ADAMTS13 (r = -0.426, p < 0.05), and GMP-140 was negatively correlated with ADAMTS13 (r = -0.398, p < 0.05). At day 4, plasma vWF was positively correlated with GMP-140 (r = 0.278, p < 0.05), negatively correlated with ADAMTS13 (r = -0.311, p < 0.05), and GMP-140 was negatively correlated with ADAMTS13 (r = -0.235, p < 0.05). At day 10, there was no significant correlation between vWF, GMP-140, and ADAMTS13 (p > 0.05).

CONCLUSIONS

VWF, GMP-140, and ADAMTS13 were correlated with the diameters and prognoses of CVS, DCI, aneurysms. Combined detection can help to evaluate the condition of patients with aSAH, so as to provide a guide for clinical treatment and prognosis.

Supramolecular architecture based on high-lacunary sandwich-type building blocks: synthesis, characterization, and properties

The new supramolecular compound [Fe2(AsMo7O27)2](H2en)2(NH4)8·6H2O (1) (en = ethylenediamine) has been synthesized in aqueous solution and characterized by elemental analysis, thermal analysis, and single crystal X-ray diffraction. The structural analysis has revealed that 1 represents the first example of a polyoxometalate-based sandwich-type supramolecular hybrid constructed from hexalacunary building blocks. Owing to the presence of ethylenediammonium cations, the [Fe2(AsMo7O27)2]12– units are stabilized by multiple circular hydrogen bonds extending the structure into a 2D supramolecular framework. The magnetic properties and antitumor activities of 1 have also been studied.

Hidden blood loss in anterior lumbar interbody fusion (ALIF) surgery

BACKGROUND

A retrospective study was performed to determine the factors affecting the total perioperative blood loss during anterior lumbar interbody fusion (ALIF). Measurements of intraoperative blood loss underestimate the true blood loss during surgery. Our research project was to examine the hidden blood loss in lumbar spine surgery. Hidden blood loss in elective knee and hip replacement surgeries range between 100% and 30%. Hidden blood loss was about 40% in posterior spine surgery.

METHODS

The factors analyzed included gender, body mass index (BMI), duration of surgery, type of surgery, aspiration, and number of fusion levels. Estimated blood loss (EBL) was obtained from the clinical records of patients as the blood collected from suctioning and the cumulative weight of the saturated sponges. Actual blood loss (ABL) was calculated from the estimated blood volume and hemoglobin level of patients. Hidden blood loss was calculated as the difference between ABL and EBL.

RESULTS

Seventy-eight consecutive patients who underwent ALIF were reviewed. The average values (mean±SD) for EBL and ABL were 700.1±562.3mL and 1150.6±770.0mL, respectively (P=0.001, Student's t-test). The hidden blood loss averaged 39.2% of the ABL. According to linear regression analysis, surgical duration, type of surgery, and the inclusion of the L4/5 level were independent factors contributing to the ABL (P<0.05), whereas BMI and gender did not correlate with ABL or EBL.

CONCLUSIONS

ALIF is associated with substantial perioperative hidden blood loss. Length of surgery, type of surgery, and the inclusion of L4/5 in the procedure are significant risk factors for increased blood loss.

LEVEL OF EVIDENCE

Level IV: retrospective or historical series.

3-Iodothyronamine-mediated metabolic suppression increases the phosphorylation of AMPK and induces fuel choice toward lipid mobilization

Despite broad medical application, induction of artificial hypometabolism in vitro and its biochemical consequence have been rarely addressed. This study aimed to elucidate whether 3-iodothyronamine (T1AM) induces hypometabolism in an in vitro model with activation of AMP-activated protein kinase (AMPK) and whether it leads to a switch in primary fuel from carbohydrates to lipids as observed in in vivo models. Mouse C2C12 myotube and T1AM, a natural derivative of thyroid hormone, were used in this study. The oxygen consumption rate (OCR) decreased in a dose-dependent manner in response to 0-100 μM T1AM for up to 10 h. Upon 6-h of exposure to 75 μM T1AM, the OCR was reduced to 60 vs. ~ 95% for the control. The intracellular [AMP]/[ATP] was 1.35-fold higher in T1AM-treated cells. RT-PCR and immunoblotting analyses revealed that treated cells had upregulated p-AMPK/AMPK (1.8-fold), carnitine palmitoyl transferase 1 mRNA, and pyruvate dehydrogenase kinase, and downregulated acetyl CoA carboxylase (0.4-fold) and pyruvate dehydrogenase phosphatase. The treated cells had darker periodic acid-Schiff staining with 1.2-fold greater glycogen content than controls. Taken together, the hypometabolic response of myotubes to T1AM was dramatic and accompanied by increases in both the relative abundance of AMP and AMPK activation, and fuel choice favoring lipids over carbohydrates. These results are consistent with the general trends observed for rodent models and true hibernators.

Study on the distribution and elimination of the new hormone irisin in vivo: new discoveries regarding irisin

Irisin is a newly discovered factor that is secreted by skeletal muscle and plays an important role in the homeostasis and metabolism of energy balance. This study used irisin radiolabeled with (125)I and small-animal SPECT/CT imaging to investigate the metabolic elimination and distribution of irisin in vivo. Irisin was labeled with (125)I using the Iodogen method. Small-animal SPECT/CT imaging was performed on C57/B16 mice at 15, 30, 60, 120, and 240 min after receiving a tail vein injection, and the radioactive distribution in the organs of mice was determined at 15, 60, and 120 min. Small-animal SPECT/CT imaging revealed the highest level of radioactivity in the gallbladder followed by the liver and kidney. Radioactivity decreased gradually with time in all organs. The radioactive distribution in the mice organs also showed that the highest %ID/g was in the gallbladder followed by the kidney and liver, and decreased gradually with time. The radioactivity in the gastric system reached its highest level at 60 min. Finally, our study showed the metabolic clearance of (125)I-irisin is achieved primarily through the hepatobiliary and renal system and provided the basis for the clinical application of irisin.

Contrasting effects of ethylene biosynthesis on induced plant resistance against a chewing and a piercing-sucking herbivore in rice

Ethylene is a stress hormone with contrasting effects on herbivore resistance. However, it remains unknown whether these differences are plant- or herbivore-specific. We cloned a rice 1-aminocyclopropane-1-carboxylic acid (ACC) synthase gene, OsACS2, whose transcripts were rapidly up-regulated in response to mechanical wounding and infestation by two important pests: the striped stem borer (SSB) Chilo suppressalis and the brown planthopper (BPH) Nilaparvata lugens. Antisense expression of OsACS2 (as-acs) reduced elicited ethylene emission, SSB-elicited trypsin protease inhibitor (TrypPI) activity, SSB-induced volatile release, and SSB resistance. Exogenous application of ACC restored TrypPI activity and SSB resistance. In contrast to SSB, BPH infestation increased volatile emission in as-acs lines. Accordingly, BPH preferred to feed and oviposit on wild-type (WT) plants--an effect that could be attributed to two repellent volatiles, 2-heptanone and 2-heptanol, that were emitted in higher amounts by as-acs plants. BPH honeydew excretion was reduced and natural enemy attraction was enhanced in as-acs lines, resulting in higher overall resistance to BPH. These results demonstrate that ethylene signaling has contrasting, herbivore-specific effects on rice defense responses and resistance against a chewing and a piercing-sucking insect, and may mediate resistance trade-offs between herbivores of different feeding guilds in rice.

The 9-lipoxygenase Osr9-LOX1 interacts with the 13-lipoxygenase-mediated pathway to regulate resistance to chewing and piercing-sucking herbivores in rice

Oxylipins produced by the 13-lipoxygenase (LOX) have been reported to play an important role in plant defense responses to herbivores. Yet, the role of oxylipins produced by the 9-LOX pathway in this process remains largely unknown. Here we cloned a gene encoding a chloroplast-localized 9-LOX, Osr9-LOX1, from rice. Transcriptional analysis revealed that herbivore infestation, mechanical wounding and jasmonic acid (JA) treatment either repressed or did not enhance the level of Osr9-LOX1 transcripts at early stages but did at later stages, whereas salicylic acid (SA) treatment quickly increased the transcript level of Osr9-LOX1. Antisense expression of Osr9-lox1 (as-r9lox1) decreased the amount of wound-induced (Z)-3-hexenal but increased levels of striped stem borer (SSB)-induced linolenic acid, JA, SA and trypsin protease inhibitors. These changes were associated with increased resistance in rice to the larvae of the SSB Chilo suppressalis. In contrast, although no significant differences were observed in the duration of the nymph stage or the number of eggs laid by female adults between the brown planthopper (BPH) Nilaparvata lugens that fed on as-r9lox1 lines and BPH that fed on wild-type (WT) rice plants, the survival rate of BPH nymphs that fed on as-r9lox1 lines was higher than that of nymphs that fed on WT plants, possibly because of a higher JA level. The results demonstrate that Osr9-LOX1 plays an important role in regulating an herbivore-induced JA burst and cross-talk between JA and SA, and in controlling resistance in rice to chewing and phloem-feeding herbivores.

An EAR-motif-containing ERF transcription factor affects herbivore-induced signaling, defense and resistance in rice

Ethylene responsive factors (ERFs) are a large family of plant-specific transcription factors that are involved in the regulation of plant development and stress responses. However, little to nothing is known about their role in herbivore-induced defense. We discovered a nucleus-localized ERF gene in rice (Oryza sativa), OsERF3, that was rapidly up-regulated in response to feeding by the rice striped stem borer (SSB) Chilo suppressalis. Antisense and over-expression of OsERF3 revealed that it positively affects transcript levels of two mitogen-activated protein kinases (MAPKs) and two WRKY genes as well as concentrations of jasmonate (JA), salicylate (SA) and the activity of trypsin protease inhibitors (TrypPIs). OsERF3 was also found to mediate the resistance of rice to SSB. On the other hand, OsERF3 was slightly suppressed by the rice brown planthopper (BPH) Nilaparvata lugens (Stål) and increased susceptibility to this piercing sucking insect, possibly by suppressing H(2)O(2) biosynthesis. We propose that OsERF3 affects early components of herbivore-induced defense responses by suppressing MAPK repressors and modulating JA, SA, ethylene and H(2)O(2) pathways as well as plant resistance. Our results also illustrate that OsERF3 acts as a central switch that gears the plant's metabolism towards an appropriate response to chewing or piercing/sucking insects.

SOA-based all-optical switch with subpicosecond full recovery

We investigate all-optical switching in a multi-quantum-well semiconductor optical amplifier-based nonlinear polarization switch using optical pulses with duration of 200 fs at a central wavelength of 1520 nm. We show full recovery of the switch within 600 fs, in both the gain and absorption regime. We discuss the switching and recovery mechanisms using numerical simulations that are in qualitatively good agreement with our experimental data.

Analyses of the minimum data set: comparisons of nursing home residents with multiple sclerosis to other nursing home residents

This research compares nursing home residents with multiple sclerosis (MS) at admission to other nursing home residents using the minimum data set (MDS). These comparisons include sociodemographic characteristics and health status measures, as well as treatments and procedures received. We analysed 14,009 admission assessments in the MDS for residents with MS between June 22, 1998 and December 31, 2000. We also analysed 440,642 MDS admission assessments for all residents admitted to nursing homes during the year 2000, with any admission assessments for residents with MS excluded from this comparison group. Residents with MS were significantly younger at admission than other recently admitted residents. In addition, residents with MS tended to be significantly more physically disabled and also less cognitively impaired than other residents at admission, based on analyses of several measures of physical disability and cognitive performance. Nursing homes caring for residents with MS should provide services and programs, including mental health care, that address the needs of these younger, more physically disabled, and more cognitvely intact residents.

Production of cloned goats from enucleated oocytes injected with cumulus cell nuclei or fused with cumulus cells

This study was designed to produce cloned goats from cumulus cells. Cloning donor nuclei were from cumulus cells either freshly isolated or cultured in vitro. Enucleated oocytes were either injected with cumulus cell nuclei without piezo-driven manipulator (injection method) or fused with cumulus cells (fusion method). The survival rate of cloned embryos, obtained by injection, was higher than that derived from fusion (62.7 and 45.9%, respectively). Two cloned goats were derived by fusion with in vitro cultured cumulus cells without starvation, but died shortly after natural birth, from respiratory difficulties. Their birth weights (2.23 kg and 2.03 kg) were within the normal range (2.0-2.7 kg) and postmortem analysis revealed no morphological abnormalities. The third cloned goat, derived by injection of nuclei from freshly isolated cumulus cells, weighed 3.3 kg at birth, and was 37% overweight compared with the average weight of the same species. This goat is healthy and well as this paper is being prepared. Nested PCR-RFLP analysis confirmed that all the cloned goats were derived from the donor cells.

Conditional and targeted overexpression of vascular chymase causes hypertension in transgenic mice

We cloned a rat vascular chymase (RVCH) from smooth muscle cells (SMCs) that converts angiotensin I to II and is up-regulated in SMC from spontaneously hypertensive vs. normotensive rats. To determine whether increased activity of RVCH is sufficient to cause hypertension, transgenic mice were generated with targeted conditional expression of RVCH to SMC, with the use of the tetracycline-controlled transactivator (tTA). We confirmed conditional expression of RVCH by mRNA, protein, and chymase activity in the absence, but not in the presence, of dietary doxycycline. The systolic blood pressure (mmHg), measured by carotid artery cannulation at 10-12 weeks of age, was higher in tTA+/RVCH+ mice than in nonbinary transgenic littermates (136 +/- 4 vs. 109 +/- 3) (P < 0.05), as were the diastolic and mean pressures. Hypertension was completely reversed by doxycycline, suggesting a causal link with chymase expression. Medial thickening of mesenteric arteries from tTA+/RVCH+ mice vs. littermates (0.82 +/- 0.1 vs. 0.42 +/- 0.02) (P < 0.05) was associated with increased SMC proliferation, as judged by positive immunoreactivity, with the use of an antibody to the proliferating cell nuclear antigen. These structural changes were prevented by doxycycline. Perfusion myography of mesenteric arteries from tTA+/RVCH+ mice also revealed increased vasoconstriction in response to phenylephrine and impaired metacholine-induced vasodilatation when compared with littermate controls or with the doxycyline-treated group. Our studies suggest that up-regulation of this vascular chymase is sufficient to cause a hypertensive arteriopathy, and that RVCH may be a candidate gene and a therapeutic target in patients with high blood pressure.

Reciprocal phosphorylation and regulation of endothelial nitric-oxide synthase in response to bradykinin stimulation

Endothelial nitric-oxide synthase (eNOS) is phosphorylated at Ser-1179 (bovine sequence) by Akt after growth factor or shear stress stimulation of endothelial cells, resulting in increased eNOS activity. Purified eNOS is also phosphorylated at Thr-497 by purified AMP-activated protein kinase, resulting in decreased eNOS activity. We investigated whether bradykinin (BK) stimulation of bovine aortic endothelial cells (BAECs) regulates eNOS through Akt activation and Ser-1179 or Thr-497 phosphorylation. Akt is transiently activated in BK-stimulated BAECs. Activation is blocked completely by wortmannin and LY294002, inhibitors of phosphatidylinositol 3-kinase, suggesting that Akt activation occurs downstream from phosphatidylinositol 3-kinase. BK stimulates a transient phosphorylation of eNOS at Ser-1179 that is correlated temporally with a transient dephosphorylation of eNOS at Thr-497. Phosphorylation at Ser-1179, but not dephosphorylation at Thr-497, is blocked by wortmannin and LY294002. BK also stimulates a transient nitric oxide (NO) release from BAECs with a time-course similar to Ser-1179 phosphorylation and Thr-497 dephosphorylation. NO release is not altered by wortmannin. BK-stimulated dephosphorylation of Thr-497 and NO release are blocked by the calcineurin inhibitor, cyclosporin A. These data suggest that BK activation of eNOS in BAECs primarily involves deinhibition of the enzyme through calcineurin-mediated dephosphorylation at Thr-497.

A novel vascular smooth muscle chymase is upregulated in hypertensive rats

While greater than 80% of angiotensin II (Ang II) formation in the human heart and greater than 60% in arteries appears to result from chymase activity, no cardiovascular cell-expressed chymase has been previously reported. We now describe the cloning of a full-length cDNA encoding a novel chymase from rat vascular smooth muscle cells. The cDNA encompasses 953 nucleotides, encodes 247 amino acids, and exhibits 74% and 80% homology in amino acid sequence to rat mast cell chymase I and II, respectively. Southern blot analysis indicates that the rat vascular chymase is encoded by a separate gene. This chymase was induced in hypertrophied rat pulmonary arteries, with 11-fold and 8-fold higher chymase mRNA levels in aortic and pulmonary artery smooth muscle cells from spontaneously hypertensive than in corresponding tissues from normotensive rats. We assayed the activity of the endogenous enzyme and of a recombinant, epitope-tagged chymase in transfected smooth muscle cells and showed that Ang II production from Ang I can be inhibited with chymostatin, but not EDTA or captopril. Spontaneously hypertensive rats show elevated chymase expression and increased chymostatin-inhibitable angiotensin-converting activity, suggesting a possible role for this novel enzyme in the pathophysiology of hypertension.

Electrolyte effects on electrochemical properties of osmium complex polymer modified electrodes

The electrolyte effects on the electrochemical behaviors of osmium complex polymer modified electrodes were investigated by a comparison between two osmium complexes, [Os(bpy)2(PVI)10Cl]Cl (Os-PVI10) and [Os(bpy)2(PVP)10Cl]Cl (Os-PVP10). The electrode process at Os-PVI10 modified electrodes is reaction-controlled, while a diffusion-controlled electrode process exists at Os-PVP10 modified electrodes. Both the cation and anion in supporting electrolytes strongly affect their electrochemical behaviors, such as the redox potential, wave shape and peak current. These phenomena are attributed to a change in the film structure and polymer swelling in various supporting electrolytes. The influence of electrolyte anions on the electrochemical behaviors is related to their hydrophobicity. The electrode process of Os-PVP10 depends on the pH value of solutions, exhibiting different electron transfer mechanisms.

Bradykinin activates the Janus-activated kinase/signal transducers and activators of transcription (JAK/STAT) pathway in vascular endothelial cells: localization of JAK/STAT signalling proteins in plasmalemmal caveolae

Bradykinin (BK) is an important physiological regulator of endothelial cell function. In the present study, we have examined the role of the Janus-activated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway in endothelial signal transduction through the BK B2 receptor (B2R). In cultured bovine aortic endothelial cells (BAECs), BK activates Tyk2 of the JAK family of tyrosine kinases. Activation results in the tyrosine phosphorylation and subsequent nuclear translocation of STAT3. BK also activates the mitogen-activated p44 and p42 protein kinases, resulting in STAT3 serine phosphorylation. Furthermore, Tyk2 and STAT3 form a complex with the B2R in response to BK stimulation. Under basal conditions, Tyk2, STAT3 and the B2R are localized either partially or entirely in endothelial plasmalemmal caveolae. Following BK stimulation of BAECs, however, the B2R and STAT3 are translocated out of caveolae. Taken together, these data suggest that BK activates the JAK/STAT pathway in endothelial cells and that JAK/STAT signalling proteins are localized in endothelial caveolae. Moreover, caveolar localization of the B2R and STAT3 appears to be regulated in an agonist-dependent manner.

Role of heat shock protein 90 in bradykinin-stimulated endothelial nitric oxide release

Previously we described ENAP-1, a 90-kDa protein that is tyrosine-phosphorylated in endothelial cells in response to bradykinin (BK) stimulation and is associated with endothelial nitric oxide synthase (eNOS). Subsequently, other investigators demonstrated that eNOS interacts with heat shock protein 90 (Hsp90) following stimulation of endothelial cells with vascular endothelial growth factor (VEGF), histamine, or fluid shear stress. Therefore, we tested the hypotheses that ENAP-1 and Hsp90 are the same protein and that BK activation of eNOS is dependent on Hsp90. Immunoblotting of immunoprecipitated Hsp90 with anti-phosphotyrosine antibody shows that Hsp90 is tyrosine-phosphorylated in response to BK stimulation of bovine aortic endothelial cells (BAECs). Coimmunoprecipitation of Hsp90 with anti-eNOS antibody reveals a Hsp90-eNOS complex in endothelial cells under basal conditions that is increased following BK stimulation. Taken together with the tyrosine phosphorylation data, these data suggest that ENAP-1 is Hsp90. BK-stimulated nitric oxide (NO) release is completely blocked by pretreatment with geldanamycin, a specific inhibitor of Hsp90, illustrating the importance of the Hsp90-eNOS interaction. In vitro binding assays with Hsp90-glutathione-S-transferase fusion proteins show direct binding of eNOS with the middle domain (residues 259-615) of Hsp90.

[Primary identification of organic compounds in soybean rhizospheric soil on continuous and alternate cropping and their allelopathy on soybean seed germination]

Organic compounds extracted with ethanol (OCEWE) from soybean rhizospheic soil on continuous and alternate cropping at pod-string were identified by gas chromatography-mass spectrometry (GC-MS). The results showed the compounds mainly include organic acids, alcohol, acetone, aldehyde, naphthalene phenyl and furan hydrocarbon, many of which were reported as allelochemcals. Under this experiment condition, OCEWE did not show any allelopathy on soybean seed germination and radicle growth, which might be related with their critical toxicity concentrations. In addition, the relationship between allelopathy and barrier on soybean continuous and alternate cropping was also discussed.

Modified partial hyperfractionation in radiotherapy for bulky uterine cervical cancer: reduction of overall treatment time

PURPOSE

The purpose of this study was to assess the feasibility and toxicity of modified fractionation of external beam radiation with the intention of reducing the overall treatment time (OT) by 1 week in cervical cancer.

METHODS AND MATERIALS

Thirty-one patients (Group 1, n = 31) with bulky cervical cancer (>/= 4 cm with Stage II and III, >/= 5 cm with Stage IB2) were entered into the twice a day (b.i. d.) protocol (18 Gy/10 fx in 2 weeks followed by 18 Gy/12 fx, b.i.d. in 6 days, then midline block at 36 Gy with 45 Gy to the whole pelvis and 51-59 Gy to the parametrium). These patients underwent high-dose-rate brachytherapy with 4 Gy/fx x 7 to point A, biweekly. During the same period, patients with non-bulky tumors (Group 2, n = 31) received conventional treatment and similar brachytherapy.

RESULTS

The OT of Group 1 was 7 weeks or less in 61.3%, 7.1-8 weeks in 29%, and more than 8 weeks in 9.7% (19.4%, 51.6%, and 29% in Group 2, respectively, p = 0.003). Incidences of acute complications and treatment breaks were similar in both groups. Late complication (rectal bleeding) occurred only in Group 1 (13%, 4/31), but was self-limited. Locoregional failures occurred within 2 years after completion of radiation therapy in both groups (16% and 13% in Group 1 and 2, respectively, with minimum and median follow-ups of 2 years and 34 months).

CONCLUSION

Partial hyperfractionation on the third week of radiation permitted patients to finish their treatment with shorter OT without excessive acute complications and with acceptable grade 2 late rectal bleeding complications. This treatment scheme may be an effective method for the improvement of local control of bulky cervical cancer.

Hyperglycemia enhances angiotensin II-induced janus-activated kinase/STAT signaling in vascular smooth muscle cells

We have shown previously that angiotensin II (Ang II) activates the janus-activated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway in vascular smooth muscle cells (VSMCs) and that activation of the JAK/STAT pathway is required for Ang II induction of VSMC proliferation. In the present study, we examined the effects of hyperglycemia (HG) on Ang II-induced JAK/STAT signaling events in cultured VSMCs. HG increases Ang II-induced JAK2 tyrosine phosphorylation and promotes a partial tyrosine phosphorylation of the enzyme under basal conditions. In addition, HG increases both basal and Ang II-induced complex formation of JAK2 with the Ang II AT(1) receptor. The extent of STAT1 and STAT3 tyrosine and serine phosphorylation are also increased under HG conditions. Furthermore, the tyrosine phosphorylation and activities of the SHP-1 and SHP-2 tyrosine phosphatases, enzymes that regulate Ang II-induced JAK2 tyrosine phosphorylation, are altered by HG. SHP-1, which is responsible for JAK2 tyrosine dephosphorylation in VSMC, is completely deactivated in HG, resulting in a prolonged duration of JAK2 phosphorylation under HG conditions. HG also enhances Ang II induction of VSMC proliferation. Taken together, these data suggest that HG augments Ang II induction of VSMC proliferation by increasing signal transduction through the JAK/STAT pathway.

Endothelial nitric oxide synthase interactions with G-protein-coupled receptors

The endothelial nitric oxide synthase (eNOS) is activated in response to stimulation of endothelial cells by a number of vasoactive substances including, bradykinin (BK), angiotensin II (Ang II), endothelin-1 (ET-1) and ATP. In the present study we have used in vitro activity assays of purified eNOS and in vitro binding assays with glutathione S-transferase fusion proteins to show that the capacity to bind and inhibit eNOS is a common feature of membrane-proximal regions of intracellular domain 4 of the BK B2, the Ang II AT1 and the ET-1 ETB receptors, but not of the ATP P2Y2 receptor. Phosphorylation of serine or tyrosine residues in the eNOS-interacting region of the B2 receptor results in a loss of eNOS inhibition due to a decrease in the binding affinity of the receptor domain for the eNOS enzyme. Furthermore, the B2 receptor is transiently phosphorylated on tyrosine residues in cultured endothelial cells in response to BK stimulation. Phosphorylation occurs during the time in which eNOS transiently dissociates from the receptor accompanied by a transient increase in nitric oxide production. Taken together, these data support the hypotheses that eNOS is regulated in endothelial cells by reversible and inhibitory interactions with G-protein-coupled receptors and that these interactions can be modulated by receptor phosphorylation.

Regulation of angiotensin II-induced phosphorylation of STAT3 in vascular smooth muscle cells

Ligand binding to the angiotensin II (Ang II) AT1 receptor on vascular smooth muscle cells (VSMCs) activates the Janus-activated kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. We have shown previously that the JAK2 tyrosine kinase and the Src family p59 Fyn tyrosine kinase are required for Ang II-induced STAT1 tyrosine phosphorylation in VSMCs. The mitogen-activated protein kinase phosphatase, MKP-1, is required for STAT1 tyrosine dephosphorylation. In the present study, using specific enzyme inhibitors and antisense oligonucleotides, we show that Ang II-induced tyrosine phosphorylation and nuclear translocation of STAT3 in VSMCs is mediated by p60 c-Src, whereas tyrosine dephosphorylation is mediated by calcineurin. Calcineurin is activated in response to Ang II stimulation of VSMCs and is translocated to the nucleus. In addition, we show that Ang II-induced serine phosphorylation of STAT3 in VSMCs is mediated by mitogen-activated protein kinase and that dephosphorylation is mediated by protein phosphatase 2A (PP2A). PP2A translocates to the nucleus in response to Ang II stimulation of VSMCs and forms a complex with STAT3 in an Ang II-dependent manner.

Technical and clinical comparison of two fully automated methods for the immunoassay of CA 125 in serum

The sensitivity and precision of two fully automated enzyme immunoassays, a chemiluminescent enzyme immunoassay (CLEIA) and an enzyme-linked immunosorbent assay (ELISA), for the determination of the ovarian carcinoma antigen CA 125 were evaluated by comparison with an immunoradiometric assay (IRMA). Sera were obtained from patients with ovarian carcinoma (N = 28 before treatment and N = 24 after treatment), digestive system cancer (N = 21 before treatment) and from healthy women (N = 90). The CLEIA showed a good agreement with the IRMA in terms of the positivity rate, accuracy and assay linearity, whereas the ELISA gave some false positive results. The mean value of CA 125 in the sera of healthy women was 14, 16 and 20 U/ml determined using the CLEIA, IRMA and ELISA procedures with standard deviations (SD) of 6.9, 7.3 and 8.8 U/ml, respectively. Both the reproducibility and precision of the CLEIA with coefficients of variation (CV) of 4.6% intra-assay and 7.6% inter-assay were better than those of the ELISA with CV of 6.2% intra-assay and 15.2% inter-assay (N = 16). We conclude that the CLEIA is the preferable method for CA 125 determinations and the diagnosis of ovarian carcinoma.

Elevation of expression of Smads 2, 3, and 4, decorin and TGF-beta in the chronic phase of myocardial infarct scar healing

We have previously shown that non-myocytes present in healed 8-week infarct scar overexpress transduction proteins required for initiating the elevated deposition of structural matrix proteins in this tissue. Other work suggests that TGF-beta 1 may be involved in cardiac fibrosis and myocyte hypertrophy. However, the significance of the altered TGF-beta signaling in heart failure in the chronic phase of post-myocardial infarction (MI), particularly in the ongoing remodeling of the infarct scar, remains unexplored. Patterns of cardiac TGF beta 1 and Smad 2, 3, and 4 protein expression were investigated 8 weeks after MI and were compared to relative collagen deposition in border tissues (containing remnent myocytes) and the infarct scar (non-myocytes). Both TGF-beta 1 mRNA abundance and protein levels were significantly increased in the infarct scar v control values, and this trend was positively correlated to increased collagen type I expression. Cardiac Smad 2, 3, and 4 proteins were significantly increased in border and scar tissues v control values. Immunofluorescent studies indicated that Smad proteins localized proximal to the cellular nuclei present in the infarct scar. Decorin mRNA abundance was elevated in border and infarct scar, and the pattern of decorin immunostaining was markedly altered in remote remnant heart and scar v staining patterns of control sections. Expression of T beta RI (53 kDa) protein was significantly reduced in the scar, while the 75 kDa and 110 kDa isoforms of T beta RII were unchanged and significantly increased in scar, respectively. These results indicate that TGF-beta/Smad signaling may be involved in the remodeling of the infarct scar after the completion of wound healing per se, via ongoing stimulation of matrix deposition.

Expression of Gi-2 alpha and Gs alpha in myofibroblasts localized to the infarct scar in heart failure due to myocardial infarction

OBJECTIVE

Patients surviving large transmural myocardial infarction (MI) are at risk for congestive heart failure with attendant alteration of ventricular geometry and scar remodeling. Altered Gi-2 alpha and Gs alpha protein expression may be involved in cardiac remodeling associated with heart failure, however their expression in scar tissue remains unclear.

METHODS

MI was produced in Sprague-Dawley rats by ligation of the left coronary artery. Gi-2 alpha and Gs alpha protein concentration, localization and mRNA abundance were noted in surviving left ventricle remote to the infarct, in border and in scar tissues from 8 week post-MI hearts with moderate heart failure.

RESULTS

We observed a 4.5- and 5.0-fold increase in immunoreactive Gi-2 alpha protein concentration occurs in the border and scar regions vs. control values, respectively, in 8-week post-MI rat hearts. Similarly, immunoreactive Gs alpha protein concentration was increased 3.4- and 8.2-fold, respectively, in these tissues vs. controls. Double-fluorescence labeling and phenotyping studies revealed that both Gi-2 alpha and Gs alpha proteins were localized to myofibroblasts in the infarct scar and to viable myocytes bordering the scar. Northern analysis revealed that the Gi-2 alpha/GAPDH ratio was increased in both viable and scar regions (1.24- and 1.85-fold respectively) from experimental hearts when compared to sham-operated control values when compared to noninfarcted left ventricle, the value of this ratio in scar tissue was elevated approximately 1.5 fold. The Gs alpha/GAPDH ratio was significantly increased (1.28-fold) only in the scar region vs. control.

CONCLUSION

Our results indicate a marked increase in the expression of Gi-2 alpha and Gs alpha from myofibroblasts of the infarct scar as well as remnant myocytes bordering the scar in 8-week post-MI rat hearts. We suggest that these changes may be associated with ongoing remodeling in the infarct scar in chronic post-MI phase of this experimental model.

Antiproliferative and antifibrotic effects of mimosine on adult cardiac fibroblasts

Prolyl 4-hydroxylase catalyzes the hydroxylation of collagen pro-alpha chains for the deposition of cardiac collagen. The effect of prolyl 4-hydroxylase on synthesis and degradation of collagen was studied in cultured adult cardiac fibroblasts using mimosine, a prolyl 4-hydroxylase inhibitor. Mimosine inhibited [3H]thymidine incorporation in cultured fibroblasts in a dose-dependent manner (100-600 microM). Immunofluorescence in fibroblasts and biochemical detection of mature type I collagen in culture serum revealed a strong inhibition of synthesis and secretion of mature collagens, respectively, in the presence of 200 microM mimosine. Western blot analysis for procollagen was carried out in cultured fibroblasts, and 200 microM mimosine treatment was associated with increased intracellular accumulation of procollagen from 4.14+/-0.27 to 10. 19+/-0.37 (arbitrary units). Immunofluorescence studies confirmed a marked increase of intracellular procollagens in fibroblasts treated with mimosine, which suggests a loss of coordinated monomeric procollagen synthesis and secretion of triple helical mature collagens. Modest inhibition of collagen type I mRNA abundance was observed in mimosine-treated fibroblasts, whereas no effect was noted for mRNAs of collagen type III, alpha-prolyl 4-hydroxylase or beta-prolyl 4-hydroxylase when compared to untreated control values. Treatment of fibroblasts with 200 microM mimosine was associated with elevation of matrix metalloproteinase (MMP)-9 activity. The cytotoxicity of mimosine treatment was found minimal at the concentrations indicated above. Thus the antifibrotic effects induced by mimosine on cultured adult cardiac fibroblasts was associated with inhibition of prolyl 4-hydroxylase and diminished extracellular secretion of procollagen, despite the reactive elevation of intracellular procollagen synthesis. We suggest that specific inhibition of prolyl 4-hydroxylase may provide a novel therapeutic approach for the modulation of cardiac fibrosis.

Regulation of angiotensin II-induced JAK2 tyrosine phosphorylation: roles of SHP-1 and SHP-2

Angiotensin II (ANG II) exerts its effects on vascular smooth muscle cells through G protein-coupled AT1 receptors. ANG II stimulation activates the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway by inducing tyrosine phosphorylation, activation, and association of JAK2 with the receptor. Association appears to be required for JAK2 phosphorylation. In the present study, electroporation experiments with neutralizing anti-Src homology phosphatase-1 (SHP-1) and anti-SHP-2 antibodies and time course determinations of SHP-1 and SHP-2 activation and complexation with JAK2 suggest that the tyrosine phosphatases, SHP-1 and SHP-2, have opposite roles in ANG II-induced JAK2 phosphorylation. SHP-1 appears responsible for JAK2 dephosphorylation and termination of the ANG II-induced JAK/STAT cascade. SHP-2 appears to have an essential role in JAK2 phosphorylation and initiation of the ANG II-induced JAK/STAT cascade leading to cell proliferation. The motif in the AT1 receptor that is required for association with JAK2 is also required for association with SHP-2. Furthermore, SHP-2 is required for JAK2-receptor association. SHP-2 may thus play a role as an adaptor protein for JAK2 association with the receptor, thereby facilitating JAK2 phosphorylation and activation.

Inhibitory interactions of the bradykinin B2 receptor with endothelial nitric-oxide synthase

It has been shown previously that the endothelial nitric-oxide synthase (eNOS) interacts reversibly with the plasmalemmal caveolae structural protein, caveolin-1. The eNOS-caveolin-1 interaction inhibits eNOS catalytic activity. In the present study, we show that eNOS also participates in reversible inhibitory interactions with the G protein-coupled bradykinin B2 receptor. eNOS and the B2 receptor are coimmunoprecipitated from endothelial cell lysates by antibodies directed against either of the two proteins. A glutathione S-transferase fusion protein containing intracellular domain 4 of the receptor is bound by purified recombinant eNOS in in vitro binding assays. The fusion protein selectively inhibits the activity of purified eNOS. A synthetic peptide corresponding to membrane-proximal residues 310-334 in intracellular domain 4 also potently inhibits eNOS activity (IC50 < 1 microM). Treatment of cultured endothelial cells with bradykinin or Ca2+ ionophore promotes a rapid dissociation of the eNOS.B2 receptor complex. These data demonstrate that the bradykinin B2 receptor physically associates with eNOS in a ligand- and Ca2+-dependent manner. Reversible and inhibitory membrane-docking interactions of eNOS, therefore, are not restricted to those with caveolin-1 but also occur with the bradykinin B2 receptor.

Bradykinin stimulates the tyrosine phosphorylation and bradykinin B2 receptor association of phospholipase C gamma 1 in vascular endothelial cells

Bradykinin (BK) B2 receptor signaling involves activation of phospholipase C (PLC). PLC activation by other receptors consists of either allosteric activation of PLC beta isoforms by G-proteins or tyrosine phosphorylation of PLC gamma isoforms. Because the B2 receptor is a G-protein-coupled receptor, it has been assumed that the receptor signals through PLC beta. In the present study, however, we have found that BK stimulation of IP3 production and the Ca2+ signal in endothelial cells is dependent on tyrosine phosphorylation. Furthermore, stimulation of B2 receptors in these cells is accompanied by a transient tyrosine phosphorylation of PLC gamma 1. Phosphorylation is correlated with increased IP3 production and association of PLC gamma 1 with the C-terminal intracellular domain of the B2 receptor. The B2 receptor can thus physically associate with intracellular proteins other than G-proteins. Activation of PLC gamma isoforms, rather than PLC beta isoforms, may, therefore, be primarily responsible for BK-stimulated IP3 generation in endothelial cells.