Prevention of methylmercury-triggered ROS-mediated impairment of embryo development by co-culture with adult adipose-derived mesenchymal stem cells.

Methylmercury (MeHg) is a potent toxin that exerts deleterious effects on human health via environmental contamination. Significant effects of MeHg on neuronal development in embryogenesis have been reported. Recently, our group demonstrated that MeHg exerts toxic effects on pre- and post-implantation embryonic development processes from zygote to blastocyst stage. Our results showed that MeHg impairs embryo development by induction of apoptosis through reactive oxygen species (ROS) generation that triggers caspase-3 cleavage and activation, which, in turn, stimulates p21-activated kinase 2 (PAK2) activity. Importantly, ROS were identified as a key upstream regulator of apoptotic events in MeHg-treated blastocysts. Data from the current study further confirmed that MeHg exerts hazardous effects on cell proliferation, apoptosis, implantation, and pre- and post-implantation embryo development. Notably, MeHg-induced injury was markedly prevented by co-culture with adipose-derived mesenchymal stem cells (ADMSCs) in vitro. Furthermore, ADMSC injection significantly reduced MeHg-mediated deleterious effects on embryo, placenta, and fetal development in vivo. Further investigation of the regulatory mechanisms by which co-cultured ADMSCs could prevent MeHg-induced impairment of embryo development revealed that ADMSCs effectively reduced ROS generation and its subsequent downstream apoptotic events, including loss of mitochondrial membrane potential and activation of caspase-3 and PAK2. The collective findings indicate that co-culture with mesenchymal stem cells (MSCs) or utilization of MSC-derived cell-conditioned medium offers an effective potential therapeutic strategy to prevent impairment of embryo development by MeHg.

Role of activated p21-activated kinase 2 in methylmercury-induced embryotoxic effects on mouse blastocysts.

Methylmercury (MeHg), a biotransformation product derived from mercury or inorganic mercury compounds in waterways, is a potent toxin that exerts hazardous effects on human health via environmental contamination. Previous studies have reported MeHg-induced impairment of nerve development in embryogenesis and placental development. However, the potential deleterious effects and regulatory mechanisms of action of MeHg on pre- and post-implantation embryo development are yet to be established. Experiments from the current study clearly demonstrate that MeHg exerts toxic effects on early embryonic development processes, including the zygote to blastocyst stage. Induction of apoptosis and decrease in embryo cell number were clearly detected in MeHg-treated blastocysts. Additionally, intracellular reactive oxygen species (ROS) generation and activation of caspase-3 and p21-activated protein kinase 2 (PAK2) were observed in MeHg-treated blastocysts. Importantly, prevention of ROS generation by pre-treatment with Trolox, a potent antioxidant, significantly attenuated MeHg-triggered caspase-3 and PAK2 activation as well as apoptosis. Notably, the downregulation of PAK2 via transfection of specifically targeted siRNA (siPAK2) led to marked attenuation of PAK2 activity and apoptosis and the deleterious effects of MeHg on embryonic development in blastocysts. Our findings strongly suggest that ROS serve as an important upstream regulator to trigger the activation of caspase-3, which further cleaves and activates PAK2 in MeHg-treated blastocysts. Activated PAK2 promotes apoptotic processes that, in turn, cause sequent impairment of embryonic and fetal development.

Intraductal papillary neoplasm of the bile duct presenting with hepatogastric fistula: a case report and literature review.

Intraductal papillary neoplasm of the bile duct (IPNB) is an uncommon entity characterized by papillary growth within the bile duct lumen. IPNB is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm of the pancreas, which sometimes complicates with fistula formation to adjacent organs, mainly due to high-pressure related erosion from mucin-filled ducts. However, fistula formation from IPNB is quite rare. Here we report a case of IPNB complicated with hepatogastric fistula. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) revealed disproportional dilatation of left intrahepatic duct with intraluminal soft tissue nodules and fistulous connections to gastric high body. Endoscopy revealed ulcers with two fistulous orifices at upper gastric body. The patient underwent left hepatectomy with gastric wedge resection. Histopathology examination revealed IPNB with invasive cholangiocarcinoma, directly invading to gastric wall leading to hepatogastric fistula. In summary, we have presented the clinical, imaging and pathological findings, along with a comprehensive review of relevant literature, in order to enhance the understanding of this rare condition.

Combination of Hepatitis B Virus Pre-S2 Gene Deletion Mutation and Tumor-Node-Metastasis Stage Predicts Higher Hepatocellular Carcinoma Recurrence after Curative Surgical Resection.

Hepatocellular carcinoma (HCC) is one of the most frequent and life-threatening human cancers worldwide. Despite curative resection surgery, the high recurrence rate of HCC leads to poor patient survival. Chronic hepatitis B virus (HBV) infection is a major etiological factor for HCC. HBV pre-S2 gene deletion mutation leads to the expression of an important oncoprotein called a pre-S2 mutant. It represents an independent prognostic biomarker for HCC recurrence. This study aimed to identify other independent prognostic biomarkers from clinicopathological characteristics of 75 HBV-related HCC patients receiving resection surgery and to validate their potential to be combined with pre-S2 gene deletion mutation as a combination biomarker for HCC recurrence. Patients with both the presence of pre-S2 gene deletion mutation and tumor-node-metastasis (TNM) stage IIIA-IIIC had a higher HCC recurrence risk than patients with either one or none of these two factors. Moreover, the combination of pre-S2 gene deletion mutation and TNM stage exhibited better performance than either of these two factors alone in discriminating patients from patients without HCC recurrence. Collectively, this study proposed that the TNM stage held significance as a combination biomarker with pre-S2 gene deletion mutation with a greater performance in predicting HCC recurrence after curative surgical resection.

Hybrid Organic-Inorganic Perovskite Superstructures for Ultrapure Green Emissions.

All inorganic CsPbBr3 superstructures (SSs) have attracted much research interest due to their unique photophysical properties, such as their large emission red-shifts and super-radiant burst emissions. These properties are of particular interest in displays, lasers and photodetectors. Currently, the best-performing perovskite optoelectronic devices incorporate organic cations (methylammonium (MA), formamidinium (FA)), however, hybrid organic-inorganic perovskite SSs have not yet been investigated. This work is the first to report on the synthesis and photophysical characterization of APbBr3 (A = MA, FA, Cs) perovskite SSs using a facile ligand-assisted reprecipitation method. At higher concentrations, the hybrid organic-inorganic MA/FAPbBr3 nanocrystals self-assemble into SSs and produce red-shifted ultrapure green emissions, meeting the requirement of Rec. 2020 displays. We hope that this work will be seminal in advancing the exploration of perovskite SSs using mixed cation groups to further improve their optoelectronic applications.

Prognostic Significance of Serum Albumin Level and Albumin-Based Mono- and Combination Biomarkers in Patients with Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer. Although many surgical and nonsurgical therapeutic options have been established for treating HCC, the overall prognosis for HCC patients receiving different treatment modalities remains inadequate, which causes HCC to remain among the most life-threatening human cancers worldwide. Therefore, it is vitally important and urgently needed to develop valuable and independent prognostic biomarkers for the early prediction of poor prognosis in HCC patients, allowing more time for more timely and appropriate treatment to improve the survival of patients. As the most abundant protein in plasma, human serum albumin (ALB) is predominantly expressed by the liver and exhibits a wide variety of essential biological functions. It has been well recognized that serum ALB level is a significant independent biomarker for a broad spectrum of human diseases including cancer. Moreover, ALB has been commonly used as a potent biomaterial and therapeutic agent in clinical settings for the treatment of various human diseases. This review provides a comprehensive summary of the evidence from the up-to-date published literature to underscore the prognostic significance of serum ALB level and various ALB-based mono- and combination biomarkers in the prediction of the prognosis of HCC patients after treatment with different surgical, locoregional, and systemic therapies.

High sensitivity CIP2A detection for oral cancer using a rapid transistor-based biosensor module.

Oral squamous cell carcinoma (OSCC) is one of the most common lip and oral cavity cancer types. It requires early detection via various medical technologies to improve the survival rate. While most detection techniques for OSCC require testing in a centralized lab to confirm cancer type, a point of care detection technique is preferred for on-site use and quick result readout. The modular biological sensor utilizing transistor-based technology has been leveraged for testing CIP2A, and optimal transistor gate voltage and load resistance for sensing setup was investigated. Sensitivities of 1 × 10-15 g/ml have been obtained for both detections of pure CIP2A protein and HeLa cell lysate using identical test conditions via serial dilution. The superior time-saving and high accuracy testing provides opportunities for rapid clinical diagnosis in the medical space.

Effect of Silicon Carbide Coating on Osteoblast Mineralization of Anodized Titanium Surfaces.

The objective of this study was to evaluate the influence of the titanium nanotube diameter and the effect of silicon carbide (SiC) coating on the proliferation and mineralization of pre-osteoblasts on titanium nanostructured surfaces. Anodized titanium sheets with nanotube diameters of 50 and 100 nm were used. The following four groups were tested in the study: (1) non-coated 50 nm nanotubes; (2) SiC-coated 50 nm titanium nanotubes; (3) non-coated 100 nm nanotubes and (4) SiC-coated 100 nm nanotubes. The biocompatibility and cytotoxicity of pre-osteoblasts were evaluated using a CellTiter-BlueCell Viability assay after 1, 2, and 3 days. After 3 days, cells attached to the surface were observed by SEM. Pre-osteoblast mineralization was determined using Alizarin-Red staining solution after 21 days of cultivation. Data were analyzed by a Kruskal−Wallis test at a p-value of 0.05. The results evidenced biocompatibility and non-cytotoxicity of both 50 and 100 nm diameter coated and non-coated surfaces after 1, 2 and 3 days. The statistical analysis indicates a statistically significant higher cell growth at 3 days (p < 0.05). SEM images after 3 days demonstrated flattened-shaped cells without any noticeable difference in the phenotypes between different diameters or surface treatments. After 21 days of induced osteogenic differentiation, the statistical analysis indicates significantly higher osteoblast calcification on coated groups of both diameters when compared with non-coated groups (p < 0.05). Based on these results, we can conclude that the titanium nanotube diameter did not play any role on cell viability or mineralization of pre-osteoblasts on SiC-coated or non-coated titanium nanotube sheets. The SiC coating demonstrated biocompatibility and non-cytotoxicity and contributed to an increase in osteoblast mineralization on titanium nanostructured surfaces when compared to non-coated groups.

Role of caspase-3-cleaved/activated PAK2 in brusatol-triggered apoptosis of human lung cancer A549 cells.

Brusatol, a major quassinoid extract of Bruceae fructus, is an important bioactive component with antineoplastic capacity. Several beneficial pharmacological and biological properties of brusatol have been uncovered to date, including anti-inflammatory, anticolitis, antimalarial, and anticancer activities. To confer anticancer benefits, brusatol is reported to effectively inhibit the Nrf2-mediated antioxidant response and trigger apoptotic signaling. In this study, we investigated the regulatory mechanisms underlying apoptotic processes in brusatol-treated A549 cells in detail. Our experiments showed that brusatol induces cell death through intracellular ROS-triggered mitochondria-dependent apoptotic events and does not involve necrosis. Mechanistically, p21-activated protein kinase 2 (PAK2) was cleaved by caspase-3 to generate an activated p34 fragment involved in brusatol-induced apoptosis of A549 cells. Notably, PAK2 knockdown led to downregulation of caspase-3-mediated PAK2 activity, in turn, effectively attenuating brusatol-induced apoptosis, highlighting a crucial role of caspase-3-activated PAK2 in this process. Moreover, knockdown of PAK2 resulted in significant inhibition of c-Jun N-terminal kinase (JNK) activity in brusatol-treated A549 cells, clearly suggesting that JNK serves as a downstream substrate of caspase-3-cleaved/activated PAK2 in the apoptotic cascade. SP600125, a specific JNK inhibitor, significantly suppressed brusatol-induced JNK activity but only partially prevented apoptosis, implying that JNK serves as only one of a number of substrates for PAK2 in the brusatol-triggered apoptotic cascade. Based on the collective results, we propose a signaling cascade model for brusatol-induced apoptosis in human A549 cells involving ROS, caspases, PAK2, and JNK.

The combination of sarcopenia and biochemical factors can predict the survival of hepatocellular carcinoma patients receiving transarterial chemoembolization.

Background: Transarterial chemoembolization(TACE) is the suggested treatment for hepatocellular carcinoma (HCC) not amenable to curative treatments. We investigated the role of sarcopenia on overall survival in HCC patients receiving TACE and proposed a new prognostic scoring system incorporating sarcopenia. Materials and methods: We retrospectively analyzed 260 HCC patients who received TACE between 2010 and 2015. Total psoas muscle was measured on a cross-sectional CT image before the first TACE session. Sarcopenia was defined by the pre-determined sex-specific cutoff value. We assessed the impact of sarcopenia and other biochemical factors on the overall survival and compared the new scoring system with other prognostic scoring systems. Results: One hundred and thirty patients (50%) were classified as sarcopenia before the first TACE. They were older with a higher male tendency and a significantly lower body mass index (BMI). Cox regression multivariate analysis demonstrated that sarcopenia, multiple tumors, maximal tumor diameter≥ 5cm, major venous thrombosis, sarcopenia, AFP ≥ 200 ng/ml, and albumin<3.5mg/dL were independent poor prognostic factors for overall survival in HCC patients receiving TACE. Our scoring system comprising these factors outperformed other major scoring systems in terms of predicting survival after TACE. Conclusion: The current study demonstrated that sarcopenia was an independent prognostic factor for HCC undergoing TACE therapy. Our newly developed scoring system could effectively predict patient survival after TACE. Physicians could, based on the current score model, carefully select candidate patients for TACE treatment in order to optimize their survival. Further studies are warranted to validate our findings.

Digital biosensor for human cerebrospinal fluid detection with single-use sensing strips.

Leakage of human cerebrospinal fluid (CSF) caused by trauma or other reasons presents exceptional challenges in clinical analysis and can have severe medical repercussions. Conventional test methods, including enzyme-linked immunosorbent assay and immunofixation electrophoresis testing, typically are performed at a few clinical reference laboratories, which may potentially delay proper diagnosis and treatment. At the same time, medical imaging can serve as a secondary diagnosis tool. This work presented here reports the use of a point-of-care electrochemical sensor for detection of beta-2-transferrin (B2T), a unique isomer of transferrin that is present exclusively in human CSF but is absent in other bodily fluids. Limits of detection were examined via serial dilution of human samples with known B2T concentrations down to 7 × 10-12 g B2T/ml while maintaining excellent sensitivity. Nine human samples with varying levels of B2T were compared using up to 100 times dilution to confirm the validity of sensor output across different patient samples.

Rapid SARS-CoV-2 diagnosis using disposable strips and a metal-oxide-semiconductor field-effect transistor platform.

The SARS-CoV-2 pandemic has had a significant impact worldwide. Currently, the most common detection methods for the virus are polymerase chain reaction (PCR) and lateral flow tests. PCR takes more than an hour to obtain the results and lateral flow tests have difficulty with detecting the virus at low concentrations. In this study, 60 clinical human saliva samples, which included 30 positive and 30 negative samples confirmed with RT-PCR, were screened for COVID-19 using disposable glucose biosensor strips and a reusable printed circuit board. The disposable strips were gold plated and functionalized to immobilize antibodies on the gold film. After functionalization, the strips were connected to the gate electrode of a metal-oxide-semiconductor field-effect transistor on the printed circuit board to amplify the test signals. A synchronous double-pulsed bias voltage was applied to the drain of the transistor and strips. The resulting change in drain waveforms was converted to digital readings. The RT-PCR-confirmed saliva samples were tested again using quantitative PCR (RT-qPCR) to determine cycling threshold (Ct) values. Ct values up to 45 refer to the number of amplification cycles needed to detect the presence of the virus. These PCR results were compared with digital readings from the sensor to better evaluate the sensor technology. The results indicate that the samples with a range of Ct values from 17.8 to 35 can be differentiated, which highlights the increased sensitivity of this sensor technology. This research exhibits the potential of this biosensor technology to be further developed into a cost-effective, point-of-care, and portable rapid detection method for SARS-CoV-2.

Fracture of Lithia Disilicate Ceramics under Different Environmental Conditions.

The objective of this research was to quantify the effect of surface degradation and abrasion separately and in combination on the flexural strength of lithia disilicate ceramics. Lithia disilicate disks were fabricated using the lost wax technique and pressing in vacuum. The eight groups in this pilot experiment were (i) reference, hydrated in distilled water for 24 h prior to fracture; (ii) reference, non-hydrated group; (iii) 28-day pH cycling group; (iv) 125K chewing cycle group; (v) combined pH cycling + 125K chewing cycle; (vi) constant pH 2 solution for 28 days; (vii) constant pH 7 solution for 28 days; and (viii) constant pH 10 solution for 28 days. pH cycling is a method that alternates between pH 2, 7 and 10 over 28 days. A total of 15 disks were used for each group. All the groups were tested using the biaxial piston and a three-ball flexural strength test to obtain their biaxial flexural strength. pH 2 constant immersion demonstrated the highest fracture strength and was significantly greater than all other groups (p < 0.0001). Chewing and pH cycling + chewing groups exhibited the lowest fracture strengths and were significantly lower than all other groups (p < 0.0001). The damage observed from the chewing simulator does not represent apparent clinical fractures.

Low-dose silver nanoparticles plus methyl mercury exert embryotoxic effects on mouse blastocysts via endoplasmic reticulum stress and mitochondrial apoptosis.

The health and environmental impacts of the increasing commercial use of silver nanoparticles (AgNPs) are a growing concern. Methyl mercury (MeHg) is a potent toxin that biotransforms from mercury or inorganic mercury compounds in waterways and causes dangerous environmental contamination. However, the potential interactions and combined effects of AgNPs and MeHg are yet to be established. In the current study, we showed that low/non-embryotoxic doses of AgNPs and MeHg interact synergistically to induce embryotoxicity and further explored the underlying mechanisms affecting mouse embryo development. Notably, co-treatment with noncytotoxic concentrations of AgNPs (10 µM) and MeHg (0.1 µM) triggered apoptotic processes and embryotoxicity in mouse blastocysts and evoked intracellular reactive oxygen species (ROS) generation, which was effectively blocked by preincubation with 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox), a classic antioxidant. Further experiments demonstrated that ROS serve as a key upstream inducer of endoplasmic reticulum (ER) stress and mitochondria-dependent apoptotic processes in AgNP/MeHg-induced injury of mouse embryo implantation and pre- and postimplantation development. Our results collectively indicate that AgNP and MeHg at non-embryotoxic concentrations can synergistically evoke ROS, ultimately causing embryotoxicity through promotion of ER stress and mitochondria-dependent apoptotic signaling cascades.

Gastric hydrodistension CT versus CT without gastric distension in preoperative TN staging of gastric carcinoma: analysis of single-center cancer registry.

Accurate staging of gastric cancer is essential for the selection and optimization of therapy. Hydrodistension of the stomach is recommended to improve the accuracy of preoperative staging with contrast-enhanced multidetector computed tomography (MDCT). This study compares the performance of contrast-enhanced gastric water distension versus a nondistension MDCT protocol for T and N staging and serosal invasion in comparison to surgical histopathology. After propensity score matching, 86 patients in each group were included for analysis. The overall accuracy of distension versus nondistension group in T staging was 45% (95% CI 35-56) and 55% (95% CI 44-65), respectively (p = 0.29). There was no difference in the sensitivity and specificity in individual T staging and assessment of serosal invasion (all p > 0.41). Individual stage concordance with pathology was not significantly different (all p > 0.41). The overall accuracy of N staging was the same for distension and nondistension groups (51% [95% CI 40-62]). The majority of N0 staging (78-81%) were correctly staged, whereas N3 staging cases (63-68%) were predominantly understaged. In summary, there was no significant difference in the diagnostic performance of individual TN staging and assessment of serosal invasion using MDCT with or without gastric water distension.

Scar prevention through topical delivery of gelatin-tyramine-siSPARC nanoplex loaded in dissolvable hyaluronic acid microneedle patch across skin barrier.

Currently, there is no effective method to prevent the formation of hypertrophic scars and keloids, which can cause severe physical and psychological burdens to patients. Secreted protein acidic and cysteine-rich (SPARC) is involved in wound fibrosis by modulating fibroblast functions, causing excessive collagen deposition during wound healing. Thus, the reduction in SPARC gene expression after wounding can contribute to the downstream reduction in collagen production at the wound site and prevent scar formation. In this study, a dissolvable and biocompatible hyaluronic acid (HA) microneedle patch loaded with nanoplexes containing tyramine-modified gelatin and siRNA for SPARC (siSPARC/Gtn-Tyr) was investigated for topical scar prevention. Tyramine-modified gelatin (Gtn-Tyr) provides electrostatic protection and enhances cell internalization for siSPARC. In vitro studies using human dermal fibroblasts showed that both siSPARC/Gtn-Tyr nanoplexes and siSPARC/Gtn-Tyr-loaded microneedle patches can significantly reduce SPARC gene expression (P < 0.05) and do not cause discernable cytotoxic effects. Further studies using a mouse wound model demonstrate that the siSPARC/Gtn-Tyr-loaded microneedle patch can reduce collagen production during wound healing without triggering an immune response. When Gtn-Tyr-siSPARC is administered transdermally at the wound site, effective collagen reduction is achieved through silencing of the matricellular SPARC protein, thus promising the reduction of scar formation. Overall, the siSPARC/Gtn-Tyr loaded microneedle patch can potentially provide an effective transdermal anti-fibrotic treatment.

Histone H2A ubiquitination resulting from Brap loss of function connects multiple aging hallmarks and accelerates neurodegeneration.

Aging is an intricate process characterized by multiple hallmarks including stem cell exhaustion, genome instability, epigenome alteration, impaired proteostasis, and cellular senescence. Whereas each of these traits is detrimental at the cellular level, it remains unclear how they are interconnected to cause systemic organ deterioration. Here we show that abrogating Brap, a BRCA1-associated protein essential for neurogenesis, results in persistent DNA double-strand breaks and elevation of histone H2A mono- and poly-ubiquitination (H2Aub). These defects extend to cellular senescence and proteasome-mediated histone H2A proteolysis with alterations in cells' proteomic and epigenetic states. Brap deletion in the mouse brain causes neuroinflammation, impaired proteostasis, accelerated neurodegeneration, and substantially shortened the lifespan. We further show the elevation of H2Aub also occurs in human brain tissues with Alzheimer's disease. These data together suggest that chromatin aberrations mediated by H2Aub may act as a nexus of multiple aging hallmarks and promote tissue-wide degeneration.

Tunable concentration-dependent upconversion and downconversion luminescence in NaYF4: Yb3+, Er3+@ NaYF4: Yb3+, Nd3+ core-shell nanocrystals for a dual-mode anti-counterfeiting imaging application.

Lanthanide-doped luminescent nanocrystals display both upconversion luminescence (UCL) and downconversion luminescence (DCL) properties, which offer potential applications in the second near-infrared window (NIR-II) images and biology sensors. Both UCL and DCL are sensitive to concentrations of activators. However, few works reveal the mechanism of concentration-dependent UCL and DCL. Herein, we synthesize core-shell upconversion nanocrystals (UCNCs) NaYF4: Yb3+(20%), Er3+ (2%)@NaYF4: Yb3+ (x%), Nd3+ (y%) with varying concentration of Nd and Yb ions. The UCL and DCL spectra are recorded under excitation of 980 nm and 808 nm lasers. The results indicate that the luminescence of core-shell UCNCs is influenced by the non-radiative rate between activators (Yb3+ and Nd3+) and the back energy transfer rate from Er3+ ions to activators. UCL tends to be obtained at a relatively low concentration of Yb3+ and Nd3+ ions (about 5%), whereas NIR emission tends to be obtained at a relatively high concentration of Yb3+ and Nd3+ ions (not higher than 20%). Dual-mode anti-counterfeiting imaging is successfully fabricated using core-shell UCNCs, which can be detected and distinguished by visible and infrared detectors. The visible versus infrared brightness of dual-mode anti-counterfeiting imaging can be tuned by varying the concentration of activators (Yb3+, Nd3+). Our work demonstrates concentration-dependent UCL and DCL in core-shell UCNCs, which provides reference to obtain NIR emission in the NIR-II region and adds encrypted dimensions for anti-counterfeiting patterns in the field of file encryption.

Enterococcus faecalis promotes a migratory and invasive phenotype in colon cancer cells.

Much about the role of intestinal microbes at the site of colon cancer development and tumor progression following curative resection remains to be understood. We have recently shown that collagenolytic bacteria such as Enterococcus faecalis predominate within the colon postoperatively, particularly at the site of the colon reconnection (i.e. anastomosis) in the early period of post-surgical recovery. The presence of collagenolytic bacteria at this site correlates with the tumor progression in a mouse model of post-surgical tumor development. In the present study we hypothesized, that collagenolytic bacteria, such as E. faecalis, play an important yet to be discovered role in tumor formation and progression. Therefore the aims of this study were to assess the role of collagenolytic E. faecalis on the migration and invasion of a murine colon cancer cell line. Results demonstrated that both migration and invasion were induced by E. faecalis with collagenolytic activity being required for only invasion. Bidirectional signaling in the E. faecalis-cancer cell interaction was observed by the discovering that the expression of gelE in E. faecalis, the gene required for collagenase production, is expressed in response to exposure to CT26 cells. The mechanism by which migration enhancement via E. faecalis occurs appears to be dependent on its ability to activate pro-uPA, a key element of the urokinase-plasminogen system, a pathway that is well - known to be important in cancer cell invasion and migration. Finally, we demonstrated that collagenase producing microbes preferentially colonize human colon cancer specimens.

High levels estradiol affect blastocyst implantation and post-implantation development directly in mice.

BACKGROUND: Previous studies have demonstrated that high levels of estradiol (E2) impair blastocyst implantation through effects on the endometrium; however, whether high E2 directly affects blastocysts is not well established. The present study sought to clarify the direct impacts of high E2 levels on blastocysts in vitro. METHODS: ICR virgin albino mice were used. Using an in-vitro 8-day blastocyst culture model, immunofluorescence staining for the estrogen receptor (ER), blastocyst outgrowth assays, differential staining and TUNEL assays of blastocysts, and embryo transfer, we investigated the main outcomes of exposure to different E2 concentrations (10-7 to 10-4 M) in vitro and in vivo. RESULTS: ERα and ERß expression were detected in pre-implantation stage embryos. In vitro exposure of blastocysts to 10-4 M E2 for 24 h followed by 7 days culture in the absence of E2 caused severe inhibition of implantation and post-implantation development. The late adverse effects of E2 on post-implantation development still occurred at concentrations of 10-7 to 10-5 M. In addition, blastocyst proliferation was reduced and apoptotic cells were increased following exposure to 10-4 M E2. Using an in vivo embryo-transfer model, we also showed that treatment with high E2 resulted in fewer implantation sites (38% vs. 72% in control) and greater resorption of implanted blastocysts (81% vs. 38% in control). CONCLUSION: Exposure to high E2 concentrations in vitro is deleterious to blastocyst implantation and early post-implantation development, mainly owing to direct impacts of E2 on implanting blastocysts. In clinical assisted reproductive technique (ART), high serum E2 concentrations not only affects the endometrium, but also affects blastocysts directly at the period of implantation.