We present a preliminary study demonstrating the capability of ultrasound-guided intravascular photoacoustic (IVPA) imaging to visualize the depth-resolved distribution of lipid deposits in atherosclerotic plaques in vivo. Based on the characteristic optical absorption of lipid in the near infrared wavelength range, IVPA imaging at a single, 1720 nm, wavelength was used to provide a spatially resolved direct measurement of lipid content in atherosclerotic arteries. By overlaying an IVPA image with a spatially co-registered intravascular ultrasound (IVUS) image, the combined IVPA/IVUS image was used to visualize the distribution of lipid within the vessel wall. Ultrasound-guided IVPA imaging was performed in vivo in the abdominal aorta of a Watanabe heritable hyperlipidemic (WHHL) rabbit. Subsequently, the excised rabbit aorta filled with a solution of red blood cells (RBC) was then imaged ex vivo, and the histology was obtained in the section adjacent to the imaged cross-section. To demonstrate the potential of future clinical application of IVPA/IVUS imaging, a sample of diseased human right coronary artery (RCA) was also imaged. Both in vivo and ex vivo IVPA images clearly showed the distribution of lipid in the atherosclerotic vessels. In vivo IVPA imaging was able to identify diffuse, lipid-rich plaques in the WHHL rabbit model of atherosclerosis. Furthermore, IVPA imaging at a single wavelength was able to identify the lipid core within the human RCA ex vivo. Our results demonstrate that ultrasound-guided IVPA imaging can identify lipid in atherosclerotic plaques in vivo. Importantly, the IVPA/IVUS images were obtained in presence of luminal blood and no saline flush or balloon occlusion was required. Overall, our studies suggest that ultrasound-guided IVPA imaging can potentially be used for depth-resolved visualization of lipid deposits within the anatomical context of the vessel wall and lumen. Therefore, IVUS/ IVPA imaging may become an important tool for the detection of rupture-prone plaques.
intravascular photoacoustic; intravascular ultrasound; plaque characterization; lipid
Resveratrol, a naturally occurring polyphenolic compound, has been reported to exert anticancer activity by affecting diverse molecular targets. In this study, we examined the effects and the underlying mechanisms of resveratrol on gastric cancer. We found that resveratrol inhibited the proliferation of gastric cancer cells in a dose-dependent manner. At the concentration of 25 and 50 µM, resveratrol inhibited the cell viability and diminished the clonogenic potential of gastric cancer cells. Resveratrol treatment arrested gastric cancer cells in the G1 phase and led to senescence instead of apoptosis. Regulators of the cell cycle and senescence pathways, including cyclin D1, cyclin-dependent kinase (CDK4 and 6), p21 and p16, were dysregulated by resveratrol treatment. The inhibitory effects of resveratrol on gastric cancer were also verified in vivo using a nude mice xenograft model. Resveratrol (40 mg/kg/d) exerted inhibitory activities on gastric cancer development and significantly decreased the fractions of Ki67-positive cells in the tumor specimens from the nude mice. After resveratrol treatment, the induction of senescence and the changes in the expression of the regulators involved in the cell cycle and senescence pathways were similar to what we observed in vitro. However, the depletion of Sirtuin (Sirt)1 reversed the above-described effects of resveratrol both in vitro and in vivo. Our data suggest that resveratrol inhibits gastric cancer in a Sirt1-dependent manner and provide detailed evidence for the possibility of applying resveratrol in gastric cancer prevention and therapy.
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death in China. This study investigated the effects of Annexin A7 (ANXA7) on the inhibition of HCC lymph node metastasis in a mouse model.
The stable knockup and knockdown of Annexin A7-expressing HCC cells using Annexin A7 cDNA and shRNA vectors, respectively, were injected into a mouse footpad to establish primary and metastatic tumors in mice. On the 14th, 21st, and 28th days after HCC cells inoculation, the mice were sacrificed for inspection of primary and secondary tumors and immunohistochemistry of Annexin A7 expression.
The lymph node metastasis rate of the FANXA7-control group was 77%, and the lymph node metastasis rate of the FANXA7-down group was 100% (p < 0.05). In contrast, the lymph node metastasis rate of the PANXA7-up group was 0% and that of the PANXA7-control group was 36% (p < 0.05). Furthermore, immunohistochemistry experiments revealed that the subcellular localization of Annexin A7 protein in both primary and lymph node-metastasized tumors was mainly in the cytosol. In addition, the expression of the 47 kDa and 51 kDa isoforms of Annexin A7 protein changed during tumor progression.
This study indicated that Annexin A7 expression was able to inhibit HCC lymph node metastasis, whereas knockdown of Annexin A7 expression significantly induced HCC metastasis to local lymph nodes.
Annexin A7; Lymph node metastasis; HCC; Gene transfection; Animal experiment
Residual β-cells found at the time of clinical onset of type 1 diabetes are sufficient to control hyperglycemia if rescued from ongoing autoimmune destruction. The challenge, however, is to develop an immunotherapy that not only selectively suppresses the diabetogenic response and efficiently reverses diabetes, but also establishes long-term β-cell–specific tolerance to maintain remission. In the current study, we show that a short course of nondepleting antibodies (Abs) specific for the CD4 and CD8 coreceptors rapidly reversed clinical disease in recent-onset diabetic NOD mice. Once established, remission was maintained indefinitely and immunity to foreign antigens unimpaired. Induction of remission involved selective T-cell purging of the pancreas and draining pancreatic lymph nodes and upregulation of transforming growth factor (TGF)-β1 by pancreas-resident antigen-presenting cells. Neutralization of TGF-β blocked the induction of remission. In contrast, maintenance of remission was associated with tissue-specific immunoregulatory T cells. These findings demonstrate that the use of nondepleting Ab specific for CD4 and CD8 is a robust approach to establish long-term β-cell–specific T-cell tolerance at the onset of clinical diabetes.
Using a glutathione S-transferase pull-down liquid chromatography–coupled tandem mass spectrometry approach and immunoprecipitation/immunoblot analysis, we found that heat shock cognate protein 70 (Hsc70) was involved in the complex formed by atypical protein kinase Cι (PKCι) and LC3 in the esophageal cancer cell line KYSE30. Further study indicated that Hsc70 was targeted by autophagic degradation, and knockdown of PKCι down-regulated Hsc70 by promoting autophagy. PKCι knockdown sensitized cells to oxidative stress-induced apoptosis, whereas forced PKCι expression counteracted the oxidative stress-induced apoptosis via Hsc70.
Electronic supplementary material
The online version of this article (doi:10.1007/s12192-012-0389-4) contains supplementary material, which is available to authorized users.
PKCι; Hsc70; Oxidative stress; Autophagic degradation
Merozoite surface protein 1 of Plasmodium vivax (PvMSP1), a glycosylphosphatidylinositol-anchored protein (GPI-AP), is a malaria vaccine candidate for P. vivax. The paralog of PvMSP1, named P. vivax merozoite surface protein 1 paralog (PvMSP1P; PlasmoDB PVX_099975), was recently identified and predicted as a GPI-AP. The similarities in genetic structural characteristics between PvMSP1 and PvMSP1P (e.g., size of open reading frames, two epidermal growth factor-like domains, and GPI anchor motif in the C terminus) led us to study this protein. In the present study, different regions of the PvMSP1P protein, demarcated based on the processed forms of PvMSP1, were expressed successfully as recombinant proteins [i.e., 83 (A, B, and C), 30, 38, 42, 33, and 19 fragments]. We studied the naturally acquired immune response against each fragment of recombinant PvMSP1P and the potential ability of each fragment to bind erythrocytes. The N-terminal fragment (83A) and two C-terminal fragments (33 and 19) reacted strongly with sera from P. vivax-infected patients, with 50 to 68% sensitivity and 95 to 96% specificity, respectively. Due to colocalization of PvMSP1P with PvMSP1, we supposed that PvMSP1P plays a similar role as PvMSP1 during erythrocyte invasion. An in vitro cytoadherence assay showed that PvMSP1P, especially the 19-kDa C-terminal region, could bind to erythrocytes. We also found that human sera from populations naturally exposed to vivax malaria and antisera obtained by immunization using the recombinant molecule PvMSP1P-19 inhibited in vitro binding of human erythrocytes to PvMSP1P-19. These results provide further evidence that the PvMSP1P might be an essential parasite adhesion molecule in the P. vivax merozoite and is a potential vaccine candidate against P. vivax.
Oral squamous cell carcinoma (OSCC) is a common malignant tumor of the head and neck, and recurrence is an important prognostic factor in patients with OSCC. We explored the factors associated with recurrence of OSCC and analyzed the survival of patients after recurrence. Clinicopathologic and follow-up data of 275 patients with OSCC treated by surgery in the Cancer Institute and Hospital of Tianjin Medical University between 2002 and 2006 were analyzed. Recurrence factors were analyzed with Chi-square or Fisher's exact test and multivariate analysis. The prognosis of patients after recurrence was analyzed with the Kaplan-Meier method and log-rank test. The recurrence rate was 32.7%. The recurrence time ranged from 2 to 96 months, with a median of 14 months. Univariate analysis showed that T stage, degree of differentiation, pN stage, flap application, resection margin, and lymphovascular invasion were factors of recurrence (P < 0.05). Multivariate analysis showed that T stage, degree of differentiation, and pN stage were independent factors of recurrence (P < 0.001). The differences in gender, age, tumor site, region of lymph node metastasis, and perineural invasion between the recurrence and non-recurrence groups were not significant (P > 0.05). Kaplan-Meier and log-rank tests showed that the 2- and 5-year survival rates were significantly lower in the recurrence group than in non-recurrence group (67.6% vs. 88.0%, 31.8% vs. 79.9%, P < 0.001). Therefore, to improve prognosis, we recommend extended local excision, flap, radical neck dissection, and adjuvant chemoradiotherapy for patients more likely to undergo recurrence.
Oral tumors; squamous cell carcinoma; recurrence; survival
We demonstrate an automated segmentation method for in-vivo 3D optical coherence tomography (OCT) imaging of the lamina cribrosa (LC). Manual segmentations of coronal slices of the LC were used as a gold standard in parameter selection and evaluation of the automated technique. The method was validated using two prototype OCT devices; each had a subject cohort including both healthy and glaucomatous eyes. Automated segmentation of in-vivo 3D LC OCT microstructure performed comparably to manual segmentation and is useful for investigative research and in clinical quantification of the LC.
(100.2000) Digital image processing; (170.4470) Ophthalmology; (110.4500) Optical coherence tomography; (170.1610) Clinical applications; (330.4460) Ophthalmic optics and devices
IL-2 plays a critical role in the induction and maintenance of FoxP3-expressing regulatory T cells (FoxP3+Treg). Reduced expression of IL-2 is linked to T cell-mediated autoimmune diseases such as Type 1 diabetes (T1D), in which an imbalance between FoxP3+Treg and pathogenic T effectors exists. We investigated the contribution of IL-2 to dysregulation of FoxP3+Treg by comparing wildtype NOD mice with animals congenic for a C57BL/6-derived disease resistant Il2 allele and in which T cell secretion of IL-2 is increased (NOD.B6Idd3). Whereas NOD mice exhibited a progressive decline in the frequency of CD62LHIFoxP3+Treg due to an increase in CD62LLOFoxP3+Treg, CD62LHIFoxP3+Treg were maintained in the pancreatic lymph nodes and islets of NOD.B6Idd3 mice. Notably, the frequency of proliferating CD62LHIFoxP3+Treg was elevated in the islets of NOD.B6Idd3 versus NOD mice. Increasing levels of IL-2 in vivo also resulted in larger numbers of CD62LHIFoxP3+Treg in NOD mice. These results demonstrate that IL-2 influences the suppressor activity of the FoxP3+Treg pool by regulating the balance between CD62LLO and CD62LHI FoxP3+Treg. In NOD mice reduced IL-2 expression leads to an increase in nonsuppressive CD62LLOFoxP3+Treg, which in turn correlates with a pool of CD62LHIFoxP3+Treg with limited proliferation.
Immunoregulation; type 1 diabetes; regulatory T cells
Objective: The aim of this study was to investigate whether four single nucleotide polymorphisms (SNPs) in CTLA-4 gene are associated with chronic obstructive pulmonary disease (COPD) in a Chinese population. Methods: Samples were collected from a Chinese population and analyzed for the association of SNPs in CTLA-4 gene with COPD in a case-control study. Four SNPs (rs231775, rs3087243, rs231725, rs5742909) in CTLA-4 gene were chosen and genotyped. The results were then analyzed using statistical methods. Results: We found that none of these four SNPs (rs231775, rs3087243, rs231725, rs5742909) in CTLA-4 gene were associated with the disease. Conclusion: Our data suggested that there was no significant association between these four SNPs in CTLA-4 gene and COPD susceptibility in a Chinese population.
CTLA-4; chronic obstructive pulmonary disease; polymorphisms
Anopheline mosquitoes are the primary vectors of parasites in the genus Plasmodium, the causative agents of malaria. Malaria parasites undergo a series of complex transformations upon ingestion by the mosquito host. During this process, the physical barrier of the midgut epithelium, along with innate immune defenses, functionally restrict parasite development. Although these defenses have been studied for some time, the regulatory factors that control them are poorly understood. The protein kinase C (PKC) gene family consists of serine/threonine kinases that serve as central signaling molecules and regulators of a broad spectrum of cellular processes including epithelial barrier function and immunity. Indeed, PKCs are highly conserved, ranging from 7 isoforms in Drosophila to 16 isoforms in mammals, yet none have been identified in mosquitoes. Despite conservation of the PKC gene family and their potential as targets for transmission-blocking strategies for malaria, no direct connections between PKCs, the mosquito immune response or epithelial barrier integrity are known. Here, we identify and characterize six PKC gene family members – PKCδ, PKCε, PKCζ, PKD, PKN, and an indeterminate conventional PKC − in Anopheles gambiae and Anopheles stephensi. Sequence and phylogenetic analyses of the anopheline PKCs support most subfamily assignments. All six PKCs are expressed in the midgut epithelia of A. gambiae and A. stephensi post-blood feeding, indicating availability for signaling in a tissue that is critical for malaria parasite development. Although inhibition of PKC enzymatic activity decreased NF-κB-regulated anti-microbial peptide expression in mosquito cells in vitro, PKC inhibition had no effect on expression of a panel of immune genes in the midgut epithelium in vivo. PKC inhibition did, however, significantly increase midgut barrier integrity and decrease development of P. falciparum oocysts in A. stephensi, suggesting that PKC-dependent signaling is a negative regulator of epithelial barrier function and a potential new target for transmission-blocking strategies.
Miscanthus is a perennial rhizomatous C4 grass native to East Asia. Endowed with great biomass yield, high ligno-cellulose composition, efficient use of radiation, nutrient and water, as well as tolerance to stress, Miscanthus has great potential as an excellent bioenergy crop. Despite of the high potential for biomass production of the allotriploid hybrid M. ×giganteus, derived from M. sacchariflorus and M. sinensis, other options need to be explored to improve the narrow genetic base of M. ×giganteus, and also to exploit other Miscanthus species, including M. sinensis (2n = 2x = 38), as bioenergy crops. In the present study, a large number of 459 M. sinensis accessions, collected from the wide geographical distribution regions in China, were genotyped using 23 SSR markers transferable from Brachypodium distachyon. Genetic diversity and population structure were assessed. High genetic diversity and differentiation of the germplasm were observed, with 115 alleles in total, a polymorphic rate of 0.77, Nei’s genetic diversity index (He) of 0.32 and polymorphism information content (PIC) of 0.26. Clustering of germplasm accessions was primarily in agreement with the natural geographic distribution. AMOVA and genetic distance analyses confirmed the genetic differentiation in the M. sinensis germplasm and it was grouped into five clusters or subpopulations. Significant genetic variation among subpopulations indicated obvious genetic differentiation in the collections, but within-subpopulation variation (83%) was substantially greater than the between-subpopulation variation (17%). Considerable phenotypic variation was observed for multiple traits among 300 M. sinensis accessions. Nine SSR markers were found to be associated with heading date and biomass yield. The diverse Chinese M. sinensis germplasm and newly identified SSR markers were proved to be valuable for breeding Miscanthus varieties with desired bioenergy traits.
High-risk human papillomavirus type 16 (HPV16) is a risk factor for cervical cancer. Previous studies suggest that polymorphisms in the E6 gene or the long control region(LCR)of HPV16 may alter the oncogenic potential of the virus. The aims of this study were to investigate the genetic variations of HPV16 E6 gene and LCR in isolates from Chinese population and correlation of the E6 and LCR polymorphisms with disease status of infected patients.
HPV16 positive endocervical specimens were collected from 304 women living in Northeast of China. Sequences of E6 gene and LCR were analyzed by PCR-sequencing.
Two lineages were found in the populations, including EUR lineage and As lineage. Based on the HPV16 prototype, the most frequent variation in the E6 gene was T178A/G (48.7%), followed by mutations of G94A (12.2%) and T350G (9.9%). The rank orders of incidence of E6 variations in amino acid were as follows: D25E (46.3%), L83V (9.9%) and H78Y (4.3%). Nucleotide variations in LCR were found in all the 304 isolates from HPV16 positive cervical samples. The most commonly observed LCR variations were the transition replacement G7193T, 7434CIns, G7521A and 7863ADel (100%). The As lineage was associated with HPV persistent infections and with disease status of ≥CIN2,3. The EUR lineage variants showed a negative trend of association with the severity of ≥CIN2,3. Among 41 variations found in LCR, 25 (61.0%) were located at the binding sites for transcription factors. Occurrence of ≥CIN2,3 was significantly associated with the mutations of R10G/L83V in E6 and the C7294T co-variation in LCR, after adjusting for ages of infected patients.
Associations between As lineage and HPV persistent infections, and with disease status of ≥CIN2,3, and an association between the EUR lineage and negative trend of association with the severity of ≥CIN2,3 were found in this study. An association between a co-variation of R10G/L83V in E6 and C7294T in LCR and an increased risk for developing CIN-2,3 was found in a HPV16 infected population of Chinese women. These findings indicate that HPV16 polymorphism influences development of CIN-2,3.
HPV16; E6; LCR; Cervical lesion
Identifying microRNA signatures for the different types and subtypes of cancer can result in improved detection, characterization and understanding of cancer and move us towards more personalized treatment strategies. However, using microRNA's differential expression (tumour versus normal) to determine these signatures may lead to inaccurate predictions and low interpretability because of the noisy nature of miRNA expression data. We present a method for the selection of biologically active microRNAs using gene expression data and microRNA-to-gene interaction network. Our method is based on a linear regression with an elastic net regularization. Our simulations show that, with our method, the active miRNAs can be detected with high accuracy and our approach is robust to high levels of noise and missing information. Furthermore, our results on real datasets for glioblastoma and prostate cancer are confirmed by microRNA expression measurements. Our method leads to the selection of potentially functionally important microRNAs. The associations of some of our identified miRNAs with cancer mechanisms are already confirmed in other studies (hypoxia related hsa-mir-210 and apoptosis-related hsa-mir-296-5p). We have also identified additional miRNAs that were not previously studied in the context of cancer but are coherently predicted as active by our method and may warrant further investigation. The code is available in Matlab and R and can be downloaded on http://www.cs.toronto.edu/goldenberg/Anna_Goldenberg/Current_Research.html.
Hepatic tuberculosis is uncommon, lack of specific clinical manifestations and imaging features, so it can easily be misdiagnosed in clinical. Herein, we discuss variety of its forms and summarize the diagnosis and treatment of hepatic tuberculosis in this paper. Five cases of hepatic tuberculosis are described. The diagnosis, treatment and outcome of the patients are discussed. Image examination associated with image-guided fine needle aspiration biopsy is the best diagnostic method. In our center, three patients underwent needle biopsy and confirmed hepatic tuberculosis. In addition, two patients preoperative misdiagnosed as cholangiocarcinoma were confirmed hepatic tuberculosis by postoperative pathology. Three patients underwent surgical procedures along with anti-tubercular drug therapy, two patients received only anti-tubercular drug therapy. The renal post-transplantation patient with hepatic tuberculosis eventually died of multiple organ failure (MODS). The other four patients were followed for 48~120 months, yielding no recurrence of hepatic tuberculosis. In conclusion, hepatic tuberculosis usually associated with atypical clinical manifestations. Image examination associated with image-guided fine needle aspiration biopsy is the best diagnostic method. Anti-TB treatment is effective in most of cases. However, if there are indications for surgery or difficult to diagnose, surgical procedures along with anti-tubercular drug therapy could be adopted.
Liver mass; tuberculoma; tuberculosis; TB; anti-TB
To understand the impact of gut microbes on human health and well-being it is crucial to assess their genetic potential. Here we describe the Illumina-based metagenomic sequencing, assembly and characterization of 3.3 million nonredundant microbial genes, derived from 576.7 Gb sequence, from faecal samples of 124 European individuals. The gene set, ~150 times larger than the human gene complement, contains an overwhelming majority of the prevalent microbial genes of the cohort and likely includes a large proportion of the prevalent human intestinal microbial genes. The genes are largely shared among individuals of the cohort. Over 99% of the genes are bacterial, suggesting that the entire cohort harbours between 1000 and 1150 prevalent bacterial species and each individual at least 160 such species, which are also largely shared. We define and describe the minimal gut metagenome and the minimal gut bacterial genome in terms of functions encoded by the gene set.
Circumsporozoite protein (CSP) is essential for sporozoite formation and sporozoite invasion into human hepatocyte. Previously, a recombinant P. vivax CSP based on chimeric repeats (rPvCSP-c) representing two major alleles VK210 and VK247 within central region has been designed. Naturally acquired humoral immune responses study show that antigenicity of rPvCSP-c was much higher than that of native strain. However, the serologic reactivity of rPvCSP-c was still unclear in detail.
In present study, recognition of rPvCSP-c in vivax malaria typed VK210 and VK247 alleles was assessed. VK210 typed and VK247 typed sera from adult residents reacted specifically with rPvCSP-c using protein array and immunoblot assay. Additionally, anti-rPvCSP-c serum recognized the fixed VK210 and VK247 sporozoites by immunofluorescence assay. Furthermore, statistic analysis was performed for correlational detection.
The rPvCSP-c reacted with both VK210 typed and VK247 typed P. vivax infected patient sera and anti-rPvCSP-c immune serum also reacted with VK210 and VK247 sporozoite parasites of P. vivax specifically. There was a positive correlation between increased antibody level, age of patients and also associated with pvcsp repeat number, although the level of responses did vary considerably in their reactivity to the rPvCSP-c from negative to very high level within each age group.
These data confirmed the serologic reactivity of the novel rPvCSP-c in exposed both VK210 and VK247 populations. These results strongly suggested that this recombinant CSP was biologically active and potently immunogenic across major strains and raised the prospect that this protein could be used as serologic marker.
Accumulating evidence indicates that microRNAs (miRNAs) are aberrantly expressed in human cancer and contribute to the tumorigenesis, but their roles in pancreatic cancer are still largely unknown. In this study, our data showed that miR-130b was significantly downregulated in 52 pairs of pancreatic cancer tissues and five cell lines. Furthermore, the deregulated miR-130b was correlated with worse prognosis, increased tumor size, late TNM stage, lymphatic invasion and distant metastasis. Multivariate analysis showed that miR-130b expression was a significant and independent prognostic predictor for pancreatic cancer patients. Functional studies indicated that the overexpression of miR-130b dramatically suppressed the proliferation of pancreatic cancer cells both in vitro and in vivo, which could be attributed to the induction of apoptosis and cell cycle arrest at S phase. Meanwhile, an overexpressed miR-130b remarkably inhibited the invasive ability of pancreatic cancer cells. Moreover, the dual luciferase assay revealed that STAT3 was directly targeted by miR-130b, which was further confirmed by the inverse expression of miR-130b and STAT3 in pancreatic cancer samples. Our findings suggested that miR-130b might have a considerable potential in prognosis identification and application of therapy for pancreatic cancer.
Quercetin is the most abundant flavonoid in fruit and vegetables and is believed to attenuate cardiovascular disease. We hypothesized that quercetin inhibits cardiac hypertrophy by blocking AP-1 (c-fos, c-jun) and activating PPAR-γ signaling pathways.
The aim of this study was to identify the mechanism underlying quercetin-mediated attenuation of cardiac hypertrophy. Quercetin therapy reduced blood pressure and markedly reduced the ratio of left ventricular to body weight (LVW/BW) (P<0.05, vs. spontaneously hypertensive rats (SHRs)). In vitro, quercetin also significantly attenuated Ang II-induced H9C2 cells hypertrophy, as indicated by its concentration dependent inhibitory effects on [3H]leucine incorporation into H9C2 cells (64% reduction) and by the reduced hypertrophic surface area in H9C2 cells compared with the Ang II group (P<0.01, vs. Ang II group). Concurrently, we found that PPAR-γ activity was significantly increased in the quercetin-treated group both in vivo and in vitro when analyzed using immunofluorescent or immunohistochemical assays (P<0.05, vs. SHRs or P<0.01, vs. the Ang II group). Conversely, in vivo, AP-1 (c-fos, s-jun) activation was suppressed in the quercetin-treated group, as was the downstream hypertrophy gene, including mRNA levels of ANP and BNP (P<0.05, vs. SHRs). Additionally, both western blotting and real time-PCR demonstrated that PPAR-γ protein and mRNA were increased in the myocardium and AP-1 protein and mRNA were significantly decreased in the quercetin-treated group (P<0.05, vs. SHRs). Furthermore, western blotting and real time-PCR analyses also showed that transfection with PPAR-γ siRNA significantly increased AP-1 signaling and reversed the effects of quercetin inhibition on mRNA expression levels of genes such as ANP and BNP in hypertrophic H9C2 cells.
Our data indicate that quercetin may inhibit cardiac hypertrophy by enhancing PPAR-γ expression and by suppressing the AP-1 signaling pathway.
Clinical observations and epidemiological surveys indicated that the prevalence of hypertension and heart diseases is increased in cold regions or during winter. Cold exposure increased NADPH oxidase gp91phox protein expression in heart, kidneys, and aorta in rats. The aim of this study was to investigate if RNA interference (RNAi) silencing of gp91phox would attenuate cold-induced hypertension and cardiovascular and renal damage. The recombinant adeno-associated virus serotype 2 (AAV-2) vector carrying gp91phox-shRNA (gp91-shRNA) was constructed for inhibiting gp91phox protein expression in cold-exposed rats. Blood pressure (BP) was monitored using a telemetry system. BP was increased in the Control-shRNA and PBS groups within 1 week of exposure to moderate cold (5°C) and reached a plateau after 7 weeks. The cold-induced increase in BP was attenuated significantly by intravenous delivery of gp91-shRNA (1.25×1010 particles/rat, 0.5 mL). One single dose of gp91-shRNA controlled hypertension for up to 10 weeks. In addition, gp91-shRNA reversed cold-induced vascular dysfunction. gp91-shRNA abolished the cold-induced up-regulation of gp91phox protein expression in heart, kidneys, and aorta, confirming effective silencing of gp91phox. The cold-induced increases in NADPH oxidase activity and superoxide production were eliminated by silencing of gp91phox, suggesting that the cold-induced up-regulation of NADPH oxidase activity may be attributed to the increased gp91phox protein expression. RNAi silencing of gp91phox abolished cold-induced cardiac and renal hypertrophy and attenuated aortic, coronary, and renal remodeling. The up-regulation of gp91phox may play a critical role in cold-induced cardiovascular dysfunction and organ damage. AAV delivery of gp91-shRNA may be a new and effective therapeutic approach for cold-related cardiovascular disorders.
Wang and colleagues investigate silencing of gp91phox as a potential way to attenuate cold-induced hypertension and cardiovascular and renal damage. Recombinant adeno-associated virus serotype 2 (AAV2) carrying gp91phox–short hairpin RNA was constructed and delivered to cold-exposed rats. A single dose of vector controlled hypertension for up to 10 weeks and reversed cold-induced vascular dysfunction as well as renal hypertrophy.
Transcriptional regulation of miRNAs that control the pathogenesis of breast cancer remains largely unknown. Here, we showed that ionizing radiation, a known breast carcinogen, triggered the differential expression of miR-20b in mammary tissues. We identified several GC-rich consensus binding motifs for the zinc finger transcription factor early growth response-1 (EGR1) in miR-20b promoter. miR-20b was upregulated by IR and its upregulation correlated with EGR1 expression in the breast cancer cell line HCC1806. Therefore, we used HCC1806 cells as a model system to explore the role of EGR1 in miR-20b transcription. siRNA knockdown of EGR1 attenuated miR-20b expression. Luciferase assays showed that whereas EGR1 stimulated luciferase activity driven by the wild-type miR-20b promoter, this induction was abolished in the mutant miR-20 promoter construct. We noted significant enrichment of EGR1 at miR-20b promoter in HCC1806 cells compared with normal human mammary epithelial cells. Suppression of miR-20b significantly inhibited HCC1806 cell proliferation and migration, and led to G 0/G 1 and S phase arrest. In vitro RNA-pull down assays indicated that miR-20b targets numerous tumor suppressors, including PTEN and BRCA1, which were downregulated in HCC1806. Conversely, suppression of miR-20b increased PTEN and BRCA1 levels. Moreover, immunohistochemical and FISH analyses showed that the miR-20b expression correlated significantly with EGR1 levels in breast cancer tissues. Our findings thus demonstrate for the first time that EGR1 is a key player in the transcriptional control of miR-20b, and miR-20b may in turn function as an oncogene by contributing to breast tumorigenesis via tumor suppressor targeting.
EGR1; miR-20b; transcription; PTEN; BRCA1; breast cancer; proliferation; migration; cell cycle arrest
Traumatic brain injury (TBI) due to falls, car accidents, and warfare affects millions of people annually. Determining personalized therapy and assessment of treatment efficacy can substantially benefit from longitudinal (4D) magnetic resonance imaging (MRI). In this paper, we propose a method for segmenting longitudinal brain MR images with TBI using personalized atlas construction. Longitudinal images with TBI typically present topological changes over time due to the effect of the impact force on tissue, skull, and blood vessels and the recovery process. We address this issue by defining a novel atlas construction scheme that explicitly models the effect of topological changes. Our method automatically estimates the probability of topological changes jointly with the personalized atlas. We demonstrate the effectiveness of this approach on MR images with TBI that also have been segmented by human raters, where our method that integrates 4D information yields improved validation measures compared to temporally independent segmentations.
4D pathology segmentation; longitudinal MRI; topological change estimation; atlas construction
Schistosomiasis is among the most prevalent human parasitic diseases, affecting more than 200 million people worldwide1. The etiological agents of this disease are trematode flatworms (Schistosoma) that live and lay eggs within the vasculature of the host. These eggs lodge in host tissues, causing inflammatory responses that are the primary cause of morbidity. Because these parasites can live and reproduce within human hosts for decades2, elucidating the mechanisms that promote their longevity is of fundamental importance. Although adult pluripotent stem cells, called neoblasts, drive long-term homeostatic tissue maintenance in long-lived free-living flatworms3,4 (e.g., planarians), and neoblast-like cells have been described in some parasitic tapeworms5, little is known about whether similar cell types exist in any trematode species. Here, we describe a population of neoblast-like cells in the trematode Schistosoma mansoni. These cells resemble planarian neoblasts morphologically and share their ability to proliferate and differentiate into derivatives of multiple germ layers. Capitalizing on available genomic resources6,7 and RNAseq-based gene expression profiling, we find that these schistosome neoblast-like cells express a fibroblast growth factor receptor ortholog. Using RNA interference we demonstrate that this gene is required for the maintenance of these neoblast-like cells. Our observations suggest that adaptation of developmental strategies shared by free-living ancestors to modern-day schistosomes likely contributed to the success of these animals as long-lived obligate parasites. We expect that future studies deciphering the function of these neoblast-like cells will have important implications for understanding the biology of these devastating parasites.