Multiple female reproductive failures in cyclooxygenase 2-deficient mice

Cyclooxygenase (COX) is the rate-limiting enzyme in the synthesis of prostaglandins (PGs) and exists in two isoforms, COX-1 and COX-2. In spite of long-standing speculation, definitive roles of PGs in various events of early pregnancy remain elusive. We demonstrate herein that the targeted disruption of COX-2, but not COX-1, in mice produces multiple failures in female reproductive processes that include ovulation, fertilization, implantation, and decidualization. Using multiple approaches, we conclude that these defects are the direct result of target organ-specific COX-2 deficiency but are not the result of deficiency of pituitary gonadotropins or ovarian steroid hormones, or reduced responsiveness of the target organs to their respective hormones.

Molecular cues to implantation

Successful implantation is the result of reciprocal interactions between the implantation-competent blastocyst and receptive uterus. Although various cellular aspects and molecular pathways of this dialogue have been identified, a comprehensive understanding of the implantation process is still missing. The receptive state of the uterus, which lasts for a limited period, is defined as the time when the uterine environment is conducive to blastocyst acceptance and implantation. A better understanding of the molecular signals that regulate uterine receptivity and implantation competency of the blastocyst is of clinical relevance because unraveling the nature of these signals may lead to strategies to correct implantation failure and improve pregnancy rates. Gene expression studies and genetically engineered mouse models have provided valuable clues to the implantation process with respect to specific growth factors, cytokines, lipid mediators, adhesion molecules, and transcription factors. However, a staggering amount of information from microarray experiments is also being generated at a rapid pace. If properly annotated and explored, this information will expand our knowledge regarding yet-to-be-identified unique, complementary, and/or redundant molecular pathways in implantation. It is hoped that the forthcoming information will generate new ideas and concepts for a process that is essential for maintaining procreation and solving major reproductive health issues in women.

Cyclo-oxygenase-2-derived prostacyclin mediates embryo implantation in the mouse via PPARdelta

We have demonstrated previously that cyclo-oxygenase-2 (COX2), the rate-limiting enzyme in the biosynthesis of prostaglandins (PGs), is essential for blastocyst implantation and decidualization. However, the candidate PG(s) that participates in these processes and the mechanism of its action remain undefined. Using COX2-deficient mice and multiple approaches, we demonstrate herein that COX2-derived prostacyclin (PGI2) is the primary PG that is essential for implantation and decidualization. Several lines of evidence suggest that the effects of PGI2 are mediated by its activation of the nuclear hormone receptor PPARdelta, demonstrating the first reported biologic function of this receptor signaling pathway.

Mechanisms of reduced fertility in Hoxa-10 mutant mice: uterine homeosis and loss of maternal Hoxa-10 expression

The establishment of a receptive uterine environment is critical for embryonic survival and implantation. One gene that is expressed in the uterus during the peri-implantation period in mice and is required for female fertility is the homeobox gene Hoxa-10. Here we characterize the peri-implantation defects in Hoxa-10 mutant females and investigate functions of Hoxa-10 in the uterine anlage during morphogenesis and in the adult uterus during pregnancy. Examination of pregnancy in Hoxa-10 mutant females has revealed failure of implantation as well as resorption of embryos in the early postimplantation period. Morphologic analysis of the mutant uterus has demonstrated homeotic transformation of the proximal 25% into oviduct. Histology and molecular markers confirm this anterior transformation. Furthermore, in situ hybridization shows that this region coincides with the anterior limit of embryonic Hoxa-10 expression in the urogenital ducts and a parallel transformation is observed in Hoxa-10 mutant males at the junction of the epididymis and ductus deferens. Female fertility could be compromised by either the homeotic transformation or the absence of Hoxa-10 function in the adult during pregnancy. To distinguish between these two potential mechanisms of infertility, wildtype blastocysts were transferred into mutant uteri distal to the transformed region on day 2.5 of pseudopregnancy. This procedure did not rescue the phenotype, suggesting that adult uterine expression of Hoxa-10 is required during pregnancy. Moreover, when implantation was experimentally delayed, homozygous uteri were able to support survival of blastocysts comparable to wild-type controls, indicating that the requirement for Hoxa-10 is intrinsic to implantation. While expression of LIF and HB-EGF appears unaffected in the mutant uteri, a decrease is observed in the intensity and number of blue dye reactions, an indicator of increased vascular permeability in response to implantation. In addition, mutant uteri exhibited decreased decidualization in response to artificial stimuli. These results show that Hoxa-10 is required during morphogenesis for proper patterning of the reproductive tract and in the adult uterus for peri-implantation events.

Differential activation of signal transduction pathways in human hearts with hypertrophy versus advanced heart failure

BACKGROUND

Left ventricular failure is commonly preceded by a period of hypertrophy. Intriguingly, many of the signaling pathways that have been implicated in the regulation of hypertrophy, including the 3 mitogen-activated protein kinases (MAPKs: extracellular signal-regulated kinase, stress-activated protein kinase, and p38), protein phosphatase, calcineurin, and the protein kinase Akt and its target glycogen synthase kinase-3 (GSK-3), also regulate the apoptotic response.

METHODS AND RESULTS

To understand the mechanisms that might regulate the progression of heart failure, we analyzed the activity of these signaling pathways in the hearts of patients with advanced heart failure, patients with compensated cardiac hypertrophy, and normal subjects. In patients with hypertrophy, neither the MAPK nor the Akt/GSK-3 pathways were activated, and the dominant signaling pathway was calcineurin. In failing hearts, calcineurin activity was increased but less so than in the hypertrophied hearts, and all 3 MAPKs and Akt were activated (and, accordingly, GSK-3ss was inhibited), irrespective of whether the underlying diagnosis was ischemic or idiopathic cardiomyopathy.

CONCLUSIONS

In the failing heart, there is a clear prohypertrophic activity profile, likely occurring in response to increased systolic wall stress and neurohormonal mediators. However, with the activation of these hypertrophic pathways, potent proapoptotic and antiapoptotic signals may also be generated. Therapies directed at altering the balance of activity of these signaling pathways could potentially alter the progression of heart failure.

The psychological burden of peanut allergy as perceived by adults with peanut allergy and the parents of peanut-allergic children

BACKGROUND

Peanut-allergic patients are affected by a condition which forces them and their families to exercise extreme dietary vigilance and experience constant uncertainty throughout their lives.

OBJECTIVE

To compare the quality of life and family relations of children and adults with a peanut allergy to that of children and adults with a rheumatological disease.

METHODS

Patients with a confirmed diagnosis of peanut allergy or a rheumatological disease completed (for children less than 18 years, by proxy) self-report questionnaires regarding the impact of their condition on their quality of life and family relations. A vertical visual analogue scale and the Impact on Family Questionnaire (IFQ) served as outcome measures.

RESULTS

One hundred and fifty-three peanut-allergic children were compared with 69 children with a rheumatological disease while 37 peanut-allergic adults were compared with 42 adults with a rheumatological disease. The parents of peanut-allergic children, compared to the parents of children with a rheumatological disease, reported that their children had significantly more disruption in their daily activities. Furthermore, the parents of peanut-allergic children reported more impairment in the familial-social dimension of the IFQ. Conversely, adults with a chronic rheumatological disease reported more disruption in their family relations than peanut-allergic adults.

CONCLUSION

Given the considerable disruption in daily activities and family relations reported by the parents of peanut-allergic children, accurate diagnosis of peanut allergy is essential. Our work should make health care professionals dealing with children with confirmed peanut allergy more aware of the support that these families may require. Furthermore, we hope to motivate food industries to offer more 'peanut free' products to decrease the dietary restrictions of these patients while minimizing their potential for accidental ingestion.

Abdominal B (AbdB) Hoxa genes: regulation in adult uterus by estrogen and progesterone and repression in müllerian duct by the synthetic estrogen diethylstilbestrol (DES)

Mice deficient for the Abdominal B (AbdB) Hox gene Hoxa-10 exhibit reduced fertility due to defects in implantation. During the peri-implantation period Hoxa-10 is sequentially expressed in the uterine epithelium and stroma. These observations, combined with the stringent regulation of uterine implantation by ovarian steroids, prompted us to test whether estrogen and progesterone directly regulate the expression of Hoxa-10 and other AbdB Hoxa genes. Here we show that Hoxa-10 expression in the adult uterus is strongly activated by progesterone. This activation is blocked by the progesterone receptor antagonist RU486 and is independent of new protein synthesis. In addition, Hoxa-10 expression is repressed by estrogen in a protein synthesis-independent manner. Analysis of adjacent AbdB Hoxa genes reveals that Hoxa-9 and a-11 are also activated in a colinear fashion by progesterone but differentially regulated by estrogen. These results suggest that the regulation of AbdB Hox gene expression in the adult uterus by ovarian steroids is a property related to position within the cluster, mediated by the direct action of estrogen and progesterone receptors upon these genes. We next examined whether the embryonic expression of Hoxa10 is regulable by hormonal factors. Previous work has demonstrated that perinatal administration of the synthetic estrogen diethylstilbestrol (DES) to mice and humans produces uterine, cervical, and oviductal malformations. Certain of these phenotypes resemble those in Hoxa-10 knockout mice, suggesting that Hoxa-10 gene expression might be repressed by DES during reproductive tract morphogenesis. Exposure of the developing female reproductive tract to DES, either in vivo or in organ culture, represses the expression of Hoxa-10 in the Müllerian duct. Thus, these data not only establish a direct link between ovarian steroids and AbdB Hoxa gene expression in the adult uterus, but also provide a potential mechanism for the teratogenic effects of DES on the developing reproductive tract.

Hoxa-10 regulates uterine stromal cell responsiveness to progesterone during implantation and decidualization in the mouse

Hoxa-10 is an AbdominalB-like homeobox gene that is expressed in the developing genitourinary tract during embryogenesis and in the adult uterus during early pregnancy. Null mutation of Hoxa-10 in the mouse causes both male and female infertility. Defective implantation and decidualization resulting from the loss of maternal Hoxa-10 function in uterine stromal cells is the cause of female infertility. However, the mechanisms by which Hoxa-10 regulates these uterine events are unknown. We have identified two potential mechanisms for these uterine defects in Hoxa-10(-/-) mice. First, two PGE2 receptor subtypes, EP3 and EP4, are aberrantly expressed in the uterine stroma in Hoxa-10(-/-) mice, while expression of several other genes in the stroma (TIMP-2, MMP-2, ER, and PR) and epithelium (LIF, HB-EGF, Ar, and COX-1) are unaffected before implantation. Further, EP3 and EP4 are inappropriately regulated by progesterone (P4) in the absence of Hoxa-10, while PR, Hoxa-11 and c-myc, three other P4-responsive genes respond normally. These results suggest that Hoxa-10 specifically mediates P4 regulation of EP3 and EP4 in the uterine stroma. Second, since Hox genes are implicated in local cell proliferation, we also examined steroid-responsive uterine cell proliferation in Hoxa-10(-/-) mice. Stromal cell proliferation in mutant mice in response to P4 and 17beta-estradiol (E2 was significantly reduced, while epithelial cell proliferation was normal in response to E2. These results suggest that stromal cell responsiveness to P4 with respect to cell proliferation is impaired in Hoxa-10(-/-) mice, and that Hoxa-10 is involved in mediating stromal cell proliferation. Collectively, these results suggest that Hoxa-10 mutation causes specific stromal cell defects that can lead to implantation and decidualization defects apparently without perturbing epithelial cell functions.

Global gene expression analysis to identify molecular markers of uterine receptivity and embryo implantation

Infertility and spontaneous pregnancy losses are an enduring problem to women's health. The establishment of pregnancy depends on successful implantation, where a complex series of interactions occurs between the heterogeneous cell types of the uterus and blastocyst. Although a number of genes are implicated in embryo-uterine interactions during implantation, genetic evidence suggests that only a small number of them are critical to this process. To obtain a global view and identify novel pathways of implantation, we used a dual screening strategy to analyze the expression of nearly 10,000 mouse genes by microarray analysis. Comparison of implantation and interimplantation sites by a conservative statistical approach revealed 36 up-regulated genes and 27 down-regulated genes at the implantation site. We also compared the uterine gene expression profile of progesterone-treated, delayed implanting mice to that of mice in which delayed implantation was terminated by estrogen. The results show up-regulation of 128 genes and down-regulation of 101 genes after termination of the delayed implantation. A combined analysis of these experiments showed specific up-regulation of 27 genes both at the implantation site and during uterine activation, representing a broad diversity of molecular functions. In contrast, the majority of genes that were decreased in the combined analysis were related to host immunity or the immune response, suggesting the importance of these genes in regulating the uterine environment for the implanting blastocyst. Collectively, we identified genes with recognized roles in implantation, genes with potential roles in this process, and genes whose functions have yet to be defined in this event. The identification of unique genetic markers for the onset of implantation signifies that genome-wide analysis coupled with functional assays is a promising approach to resolve the molecular pathways required for successful implantation.

Effects of wogonin, a plant flavone from Scutellaria radix, on skin inflammation: in vivo regulation of inflammation-associated gene expression

Flavonoids from plant origin show anti-inflammatory activity in vitro and in vivo. In addition to inhibition of inflammation-associated enzymes, such as cyclooxygenases (COX) and lipoxygenases, they have been found to regulate the expression of inflammation-associated proteins from in vitro experiments. In order to prove in vivo behavior and the potential for beneficial use against inflammatory skin disorders, the effect of wogonin (5,7-dihydroxy-8-methoxyflavone) on in vivo expression of several inflammation-associated genes was examined in the intact as well as in the inflamed mouse skin by reverse transcriptase-polymerase chain reaction analysis. When applied topically on the intact skin, only a high dose treatment of wogonin (1000 microg/ear/3 days) slightly increased COX-1 and fibronectin mRNA. On the other hand, wogonin at the doses of 250-1000 microg/ear/3 days potently lowered mRNA levels of COX-2 and tumor necrosis factor-alpha with less effect on intercellular adhesion molecule-1 and interleukin-1beta in a sub-chronic skin inflammation model of tetradecanoylphorbol-13-acetate-induced ear edema (multiple treatment). The decrease of prostaglandin E(2) concentration (27.3-34.3%) was concomitantly observed in the wogonin-treated groups. A similar effect was also observed in an acute inflammation model of arachidonic acid-induced ear edema. From the present study, wogonin was proved to differentially regulate the expression of inflammation-associated genes in vivo and to become a useful therapeutic agent for skin inflammatory diseases mainly due to its modulation of the expression of proinflammatory molecules.

Dysregulation of EGF family of growth factors and COX-2 in the uterus during the preattachment and attachment reactions of the blastocyst with the luminal epithelium correlates with implantation failure in LIF-deficient mice

Various mediators, including cytokines, growth factors, homeotic gene products, and prostaglandins (PGs), participate in the implantation process in an autocrine, paracrine, or juxtacrine manner. However, interactions among these factors that result in successful implantation are not clearly understood. Leukemia inhibitory factor (LIF), a pleiotropic cytokine, was shown to be expressed in uterine glands on day 4 morning before implantation and is critical to this process in mice. However, the mechanism by which LIF executes its effects in implantation remains unknown. Moreover, interactions of LIF with other implantation-specific molecules have not yet been defined. Using normal and delayed implantation models, we herein show that LIF is not only expressed in progesterone (P4)-primed uterine glands before implantation in response to nidatory estrogen, it is also induced in stromal cells surrounding the active blastocyst at the time of the attachment reaction. This suggests that LIF has biphasic effects: first in the preparation of the receptive uterus and subsequently in the attachment reaction. The mechanism by which LIF participates in these events was addressed using LIF-deficient mice. We observed that while uterine cell-specific proliferation, steroid hormone responsiveness, and expression patterns of several genes are normal, specific members of the EGF family of growth factors, such as amphiregulin (Ar), heparin-binding EGF-like growth factor (HB-EGF), and epiregulin, are not expressed in LIF(-/-) uteri before and during the anticipated time of implantation, although EGF receptor family members (erbBs) are expressed correctly. Furthermore, cyclooxygenase-2 (COX-2), an inducible rate-limiting enzyme for PG synthesis and essential for implantation, is aberrantly expressed in the uterus surrounding the blastocyst in LIF(-/-) mice. These results suggest that dysregulation of specific EGF-like growth factors and COX-2 in the uterus contributes, at least partially, to implantation failure in LIF(-/-) mice. Since estrogen is essential for uterine receptivity, LIF induction, and blastocyst activation, it is possible that the nidatory estrogen effects in the P4-primed uterus for implantation are mediated via LIF signaling. However, we observed that LIF can only partially resume implantation in P4-primed, delayed implanting mice in the absence of estrogen, suggesting LIF induction is one of many functions that are executed by estrogen for implantation.

Effects of flavonoids on senescence-associated secretory phenotype formation from bleomycin-induced senescence in BJ fibroblasts

During senescence, cells express molecules called senescence-associated secretory phenotype (SASP), including growth factors, proinflammatory cytokines, chemokines, and proteases. The SASP induces a chronic low-grade inflammation adjacent to cells and tissues, leading to degenerative diseases. The anti-inflammatory activity of flavonoids was investigated on SASP expression in senescent fibroblasts. Effects of flavonoids on SASP expression such as IL-1α, IL-1β, IL-6, IL-8, GM-CSF, CXCL1, MCP-2 and MMP-3 and signaling molecules were examined in bleomycin-induced senescent BJ cells. In vivo activity of apigenin on SASP suppression was identified in the kidney of aged rats. Among the five naturally-occurring flavonoids initially tested, apigenin and kaempferol strongly inhibited the expression of SASP. These flavonoids inhibited NF-κB p65 activity via the IRAK1/IκBα signaling pathway and expression of IκBζ. Blocking IκBζ expression especially reduced the expression of SASP. A structure-activity relationship study using some synthetic flavones demonstrated that hydroxyl substitutions at C-2',3',4',5 and 7 were important in inhibiting SASP production. Finally, these results were verified by results showing that the oral administration of apigenin significantly reduced elevated levels of SASP and IκBζ mRNA in the kidneys of aged rats. This study is the first to show that certain flavonoids are inhibitors of SASP production, partially related to NF-κB p65 and IκBζ signaling pathway, and may effectively protect or alleviate chronic low-grade inflammation in degenerative diseases such as cardiovascular diseases and late-stage cancer.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Mechanisms governing subcellular localization and function of human RGS2

RGS proteins negatively regulate heterotrimeric G proteins at the plasma membrane. RGS2-GFP localizes to the nucleus, plasma membrane, and cytoplasm of HEK293 cells. Expression of activated G(q) increased RGS2 association with the plasma membrane and decreased accumulation in the nucleus, suggesting that signal-induced redistribution may regulate RGS2 function. Thus, we identified and characterized a conserved N-terminal domain in RGS2 that is necessary and sufficient for plasma membrane localization. Mutational and biophysical analyses indicated that this domain is an amphipathic alpha-helix that binds vesicles containing acidic phospholipids. However, the plasma membrane targeting function of the amphipathic helical domain did not appear to be essential for RGS2 to attenuate signaling by activated G(q). Nevertheless, truncation mutants indicated that the N terminus is essential, potentially serving as a scaffold that binds receptors, signaling proteins, or nuclear components. Indeed, the RGS2 N terminus directs nuclear accumulation of GFP. Although RGS2 possesses a nuclear targeting motif, it lacks a nuclear import signal and enters the nucleus by passive diffusion. Nuclear accumulation of RGS2 does not limit its ability to attenuate G(q) signaling, because excluding RGS2 from the nucleus was without effect. RGS2 may nonetheless regulate signaling or other processes in the nucleus.

Expression of betacellulin and epiregulin genes in the mouse uterus temporally by the blastocyst solely at the site of its apposition is coincident with the "window" of implantation

In the mouse, the process of implantation is initiated by the attachment reaction between the blastocyst trophectoderm and uterine luminal epithelium that occurs at 2200-2300 h on day 4 (day 1 = vaginal plug) of pregnancy. Several members of the EGF family are considered important in embryo-uterine interactions during implantation. This investigation demonstrates that the expression of two additions to the family, betacellulin and epiregulin, are exquisitely restricted to the mouse uterine luminal epithelium and underlying stroma adjacent to the implanting blastocyst. These genes are not expressed during progesterone-maintained delayed implantation, but are rapidly switched on in the uterus surrounding the implanting blastocyst following termination of the delay by estrogen. These results provide evidence that expression of betacellulin and epiregulin in the uterus requires the presence of an active blastocyst and suggest an involvement of these growth factors in the process of implantation.

Automated classification of gastric neoplasms in endoscopic images using a convolutional neural network

BACKGROUND

Visual inspection, lesion detection, and differentiation between malignant and benign features are key aspects of an endoscopist's role. The use of machine learning for the recognition and differentiation of images has been increasingly adopted in clinical practice. This study aimed to establish convolutional neural network (CNN) models to automatically classify gastric neoplasms based on endoscopic images.

METHODS

Endoscopic white-light images of pathologically confirmed gastric lesions were collected and classified into five categories: advanced gastric cancer, early gastric cancer, high grade dysplasia, low grade dysplasia, and non-neoplasm. Three pretrained CNN models were fine-tuned using a training dataset. The classifying performance of the models was evaluated using a test dataset and a prospective validation dataset.

RESULTS

A total of 5017 images were collected from 1269 patients, among which 812 images from 212 patients were used as the test dataset. An additional 200 images from 200 patients were collected and used for prospective validation. For the five-category classification, the weighted average accuracy of the Inception-Resnet-v2 model reached 84.6 %. The mean area under the curve (AUC) of the model for differentiating gastric cancer and neoplasm was 0.877 and 0.927, respectively. In prospective validation, the Inception-Resnet-v2 model showed lower performance compared with the endoscopist with the best performance (five-category accuracy 76.4 % vs. 87.6 %; cancer 76.0 % vs. 97.5 %; neoplasm 73.5 % vs. 96.5 %; P  < 0.001). However, there was no statistical difference between the Inception-Resnet-v2 model and the endoscopist with the worst performance in the differentiation of gastric cancer (accuracy 76.0 % vs. 82.0 %) and neoplasm (AUC 0.776 vs. 0.865).

CONCLUSION

The evaluated deep-learning models have the potential for clinical application in classifying gastric cancer or neoplasm on endoscopic white-light images.

Profound apoptosis-mediated regional myocyte loss and compensatory hypertrophy in pigs with hibernating myocardium

BACKGROUND

Myocyte apoptosis is seen in ischemic heart disease, but whether it can occur after reversible ischemia or independent of necrosis and replacement fibrosis is unknown.

METHODS AND RESULTS

Pigs were instrumented with a stenosis of the left anterior descending coronary artery to chronically reduce coronary flow reserve over a period of 3 months. At this time, there was viable dysfunctional myocardium having the physiological features of hibernating myocardium. Resting subendocardial perfusion was reduced to 0.65+/-0.08 (mean+/-SEM) mL. min(-1). g(-1) in hibernating myocardium of instrumented pigs compared with 0.98+/-0.14 mL. min(-1). g(-1) in myocardium of sham-operated pigs (P<0.05). There was a critical limitation in subendocardial flow during vasodilation to 0.78+/-0.20 mL. min(-1). g(-1) in instrumented pigs versus 3. 24+/-0.50 mL. min(-1). g(-1) in sham-operated pigs (P<0.001). Histology revealed a regional reduction in myocyte nuclear density to 995+/-100 nuclei/mm(2) in hibernating myocardium from the instrumented group versus 1534+/-65 nuclei/mm(2) in myocardium from the sham-operated group (P<0.05), regional myocyte hypertrophy (myocyte volume per nucleus, 14 183+/-2594 in the instrumented group versus 9130+/-1301 microm(3) in the sham group; P<0.05), and minimal increases in connective tissue (5.8+/-0.9% in the instrumented group versus 3.0+/-0.2% in the sham group, P<0.05). Necrosis was not identified, but apoptosis was increased from 30+/-9 myocytes per 10(6) myocyte nuclei in myocardium from the sham group to 220+/-77 myocytes per 10(6) myocyte nuclei in hibernating myocardium (P<0.05).

CONCLUSIONS

These findings indicate that reversible ischemia in an area of chronically reduced coronary flow reserve induces regional myocyte loss via an apoptotic mechanism. This may contribute to the progression of chronic coronary disease to heart failure and explain the lack of complete functional recovery after revascularization in hibernating myocardium.

Molecular signaling in uterine receptivity for implantation

Successful implantation is the result of an intimate 'cross-talk' between the blastocyst and uterus in a temporal and cell-specific manner. Thus, both the uterine and embryonic events must be examined to better understand this process. Although various aspects and molecules associated with these events have been explored, a comprehensive understanding of the implantation process is still very limited. In this review, we have highlighted the importance of the blastocyst's activity state and the receptive state of the uterus in determining the 'window' of implantation. In this context, we provide a testable scheme that signifies the important roles of various key molecules in embryo-uterine interactions during implantation.

Regulation of cyclooxygenase-2 induction in the mouse uterus during decidualization. An event of early pregnancy

The infertility phenotype of cyclooxygenase-2 (Cox-2)-deficient female mice establishes the important role of Cox-2 in pregnancy. Cox-2 deficiency results in defective ovulation, fertilization, implantation, and decidualization; the latter of which can be restored in part by the prostacyclin analog carbaprostacyclin. Uterine Cox-2 expression during early pregnancy shows distinct localization and kinetics in the uterine luminal epithelium and underlying stromal cells, suggesting that expression is tightly regulated. Several intracellular signaling cascades including ERK, p38, and JNK are implicated in vitro as critical components of regulated Cox-2 expression in response to mitogens, growth factors, and cytokines. We investigated the involvement of these signaling pathways during Cox-2 induction in vivo by monitoring uterine kinase activity after intraluminal application of a deciduogenic stimulus. Our results show that the ERK and p38 pathways are activated in uterine preparations as early as 5-min post-stimulation. ERK activation was sustained for several hours with a return to baseline levels by 4 h. p38 activation was rapid with a peak at 5-min post-stimulation and returned to near baseline levels after 45 min. Systemic administration of a MEK inhibitor completely inhibited ERK activation, but did not affect early (2 h) luminal epithelial or late (24 h) stromal Cox-2 expression and only modestly affected decidualization. In contrast, administration of a p38 inhibitor modestly inhibited early Cox-2 expression in the luminal epithelium, while dramatically diminishing late stromal expression. In parallel, induced stromal peroxisomal proliferator activated receptor-delta (PPARdelta) expression is blunted by p38 inhibition. p38 inhibition also significantly inhibited decidualization. These results suggest that p38, but not ERK, activation is required for induced Cox-2 and PPARdelta expression during decidualization. In addition, inhibition of p38 led to decreased decidualization suggesting that an intracrine prostanoid pathway consisting of Cox-2, prostacyclin, and PPARdelta is required for maintenance of early pregnancy.

Anti-inflammatory activity of pectolinarigenin and pectolinarin isolated from Cirsium chanroenicum

In order to identify the active anti-inflammatory ingredient(s) in Cirsium chanroenicum (Compositae), its methanol extract and several solvent fractions were prepared; the methanol extract and the ethylacetate fraction inhibited cyclooxygenase-2 (COX-2)-mediated prostaglandin E2 (PGE2) and 5-lipoxygenase (5-LOX)-mediated leukotriene (LT) production in lipopolysaccharide-treated RAW 264.7 cells and A23187-treated rat basophilic leukemia (RBL-1) cells, respectively. Further bioactivity-guided fractionation of the ethylacetate fraction using column chromatography led to the isolation of pectolinarigenin (5,7-dihydroxy-4',6-dimethoxyflavone), along with pectolinarin [pectolinarigenin 7-rhamnosyl-(1-->6)-glucoside]. Pectolinarigenin strongly inhibited COX-2-mediated PGE2 and 5-LOX-mediated LT production at >1 microM, indicating that it is a dual inhibitor of COX-2/5-LOX. However, pectolinarigenin did not affect COX-2 expression or nuclear transcription factor (NF-kappaB) activation. In addition, in vivo studies demonstrated that oral administration of these two compounds at 20-100 mg/kg resulted in similar inhibitory activities against several animal models of inflammation/allergy: arachidonic acid-induced mouse ear edema, carrageenan-induced mouse paw edema and passive cutaneous anaphylaxis. All of these results suggest that pectolinarigenin and pectolinarin possess anti-inflammatory activity and that they may inhibit eicosanoid formation in inflammatory lesions. These activities certainly contribute to the anti-inflammatory mechanism of C. chanroenicum.

Loss of Nkx3.1 leads to the activation of discrete downstream target genes during prostate tumorigenesis

The expression of NKX3.1, a transcriptional regulator and tumor suppressor gene in prostate cancer, is downregulated during early stages of prostate tumorigenesis. However, little is known of the alterations in gene expression that occur as a result of this event. We combined laser capture microdissection and gene expression profiling to analyze the molecular consequences of Nkx3.1 loss during prostate cancer initiation using Nkx3.1-deficient mice. This analysis identified a cohort of genes (loss-of-Nkx3.1 signature) that are aberrantly overexpressed during loss-of-Nkx3.1 driven tumor initiation. We studied the expression of these same genes in independent loss-of-Pten and c-myc overexpression prostate adenocarcinoma mouse models. Nkx3.1 expression is lost in prostate epithelial proliferation in both of these mouse models. However, Nkx3.1 loss is an early event of tumor development in the loss-of-Pten model, whereas it occurs at later stages in c-myc transgenic mice. A member of genes of the loss-of-Nkx3.1 signature, like clusterin and quiescin Q6, are highly expressed in prostatic hyperplasia and intraepithelial neoplasia (PIN) lesions that also lack Nkx3.1 in the Pten-deficient prostate, but not in similar lesions in the c-myc transgenic model. Meta-analysis of multiple prostate cancer gene expression datasets including those from loss-of-Nkx3.1, loss-of-Pten, c-myc overexpression, and constitutively active Akt prostate cancer models, further confirmed that genes associated with the loss-of-Nkx3.1 signature integrate with Pten-Akt signaling pathways, but do not overlap with molecular changes associated with the c-myc signaling pathway. In human prostate tissue samples, loss of NKX3.1 expression and corresponding clusterin overexpression are co-localized at sites of prostatic inflammatory atrophy, a possible very early stage of human prostate tumorigenesis. Collectively, these results suggest that the molecular consequences of NKX3.1 loss depend on the epithelial proliferative stage at which its expression is lost and, that alterations in the Pten-Akt-Nkx3.1 axis are important for prostate cancer initiation.

Flavonoids interfere with NLRP3 inflammasome activation

NOD-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) inflammasome is a component of innate immunity, and is responsible for producing mature IL-1β and -18. Several flavonoids were found to affect inflammasome pathway, but the mechanism of action is still obscure. To elucidate the effects on NLRP3 inflammasome pathway and to determine the structure-activity relationships, NLRP3 inflammasome in differentiated THP-1 cells was activated via treatment with monosodium urate (MSU) crystals. Levels of mature IL-1β, NLRP3 inflammasome components and apoptosis-associated speck-like protein containing a CARD (caspase recruitment domain) (ASC) oligomerization were investigated and the mechanisms of action were also elucidated. Among the 56 flavonoids initially tested, only flavone, 2',4'-dihhydroxyflavone, 3',4'-dichloroflavone, 4',5,7-trihydroxyflavone (apigenin), 3,4',5,7-tetrahydroxyflavone (kaempferol) and 3,3',4',5,7-pentahydroxyflavone (quercetin) significantly inhibited IL-1β production at 10 μM. Apigenin, kaempferol and 3',4'-dichloroflavone inhibited ASC oligomerization without affecting the ASC level in cell lysates. Apigenin also inhibited absent in melanoma 2 (AIM2) inflammasome-related pathway, but not NLR family CARD domain-containing protein 4 (NLRC4) inflammasome activation. The action of apigenin on NLRP3 inflammasome activation is mediated partly via inhibition of phosphorylation of spleen tyrosine kinase/protein tyrosine kinase 2 (Syk/Pyk2) pathway. Furthermore, orally administered apigenin (100 mg/kg) strongly reduced the number of neutrophils and monocytes in MSU-induced peritonitis in mice. The present study, for the first time, demonstrated the structure-activity profiles of flavonoids in NLRP3 inflammasome activation and mechanisms of cellular action. Certain flavonoids including apigenin are expected to ameliorate the inflammatory symptoms in autoinflammatory diseases associated with NLRP3 inflammasome activation.

Generalized tube model of biased reptation for gel electrophoresis of DNA

A theoretical analysis of the reptational motion of DNA in a gel that includes the effects of molecular fluctuations has been used to explain the main features found in experiments involving periodic inversion of the electric field. The resonance-like decrease of the electrophoretic mobility as a function of pulse duration is related to transient "undershoots" in the orientation of the molecule, in agreement with recent experimental data. These features arise from a delicate interplay of internal and center of mass motion of the molecules under pulsed field conditions, and are important for the separation of DNA molecules in the size range 0.2 to 10 million base pairs.

Inhibition of mammalian collagenase, matrix metalloproteinase-1, by naturally-occurring flavonoids

Some plant flavonoids in the form of whole plant extracts have been used topically for skin inflammatory disorders. Since matrix metalloproteinase-1 (MMP-1, collagenase-1) plays an important role in unbalanced turn-over or rapid breakdown of collagen molecules in human inflamed/UV-irradiated skin, the effects of natural flavonoids on MMP-1 activity and MMP-1 expression were studied to establish the therapeutic potential. Against recombinant human MMP-1, flavonols such as quercetin and kaempferol were strong inhibitors with IC50 values of 39.6 and 43.7 microM, respectively, while flavones such as apigenin and wogonin showed only weak inhibitory activity. In addition, quercetin, kaempferol, apigenin and wogonin (12.5-25.0 microM) strongly inhibited MMP-1 induction in 12-O-tetradecanoylphorbol 13-acetate-treated human dermal fibroblasts, but naringenin (a flavanone) did not. By means of the electrophoretic mobility shift assay, these flavonoids were also found to inhibit activation of the transcription factor, activator protein-1 (AP-1). Moreover, quercetin inhibited extracellular signal-regulated protein kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) activation, and kaempferol inhibited p38 MAPK and c-Jun N-terminal kinase (JNK) activation among the MAPKs tested. In contrast, flavones and naringenin did not inhibit the activation of these three MAPKs. These results have shown, for the first time, that naturally-occurring flavonoids (quercetin, kaempferol, apigenin and wogonin) inhibit MMP-1 and down-regulate MMP-1 expression via an inhibition of the AP-1 activation although the cellular inhibitory mechanisms differ depending on their chemical structures. Therefore, certain plant flavonoids or plant extracts with these flavonoids as major components may be beneficial to treat some skin inflammatory disorders and to protect skin from photoaging.

Successful targeting of the NRG1 pathway indicates novel treatment strategy for metastatic cancer

Background

NRG1 fusion-positive lung cancers have emerged as potentially actionable events in lung cancer, but clinical support is currently limited and no evidence of efficacy of this approach in cancers beyond lung has been shown.

Patients and methods

Here, we describe two patients with advanced cancers refractory to standard therapies. Patient 1 had lung adenocarcinoma and patient 2 cholangiocarcinoma. Whole-genome and transcriptome sequencing were carried out for these cases with select findings validated by fluorescence in situ hybridization.

Results

Both tumors were found to be positive for NRG1 gene fusions. In patient 1, an SDC4-NRG1 gene fusion was detected, similar gene fusions having been described in lung cancers previously. In patient 2, a novel ATP1B1-NRG1 gene fusion was detected. Cholangiocarcinoma is not a disease type in which NRG1 fusions had been described previously. Integrative genome analysis was used to assess the potential functional significance of the detected genomic events including the gene fusions, prioritizing therapeutic strategies targeting the HER-family of growth factor receptors. Both patients were treated with the pan HER-family kinase inhibitor afatinib and both displayed significant and durable response to treatment. Upon progression sites of disease were sequenced. The lack of obvious genomic events to describe the disease progression indicated that broad transcriptomic or epigenetic mechanisms could be attributed to the lack of prolonged response to afatinib.

Conclusion

These observations lend further support to the use of pan HER-tyrosine kinase inhibitors for the treatment of NRG1 fusion-positive in both cancers of lung and hepatocellular origin and indicate more broadly that cancers found to be NRG1 fusion-positive may benefit from such a clinical approach regardless of their site of origin.

Clinical trial information

Personalized Oncogenomics (POG) Program of British Columbia: Utilization of Genomic Analysis to Better Understand Tumour Heterogeneity and Evolution (NCT02155621).