Unveiling the inhibition mechanism of Clostridioides difficile by Bifidobacterium longum via multiomics approach.

Antibiotic-induced gut microbiota disruption constitutes a major risk factor for Clostridioides difficile infection (CDI). Further, antibiotic therapy, which is the standard treatment option for CDI, exacerbates gut microbiota imbalance, thereby causing high recurrent CDI incidence. Consequently, probiotic-based CDI treatment has emerged as a long-term management and preventive option. However, the mechanisms underlying the therapeutic effects of probiotics for CDI remain uninvestigated, thereby creating a knowledge gap that needs to be addressed. To fill this gap, we used a multiomics approach to holistically investigate the mechanisms underlying the therapeutic effects of probiotics for CDI at a molecular level. We first screened Bifidobacterium longum owing to its inhibitory effect on C. difficile growth, then observed the physiological changes associated with the inhibition of C. difficile growth and toxin production via a multiomics approach. Regarding the mechanism underlying C. difficile growth inhibition, we detected a decrease in intracellular adenosine triphosphate (ATP) synthesis due to B. longum-produced lactate and a subsequent decrease in (deoxy)ribonucleoside triphosphate synthesis. Via the differential regulation of proteins involved in translation and protein quality control, we identified B. longum-induced proteinaceous stress. Finally, we found that B. longum suppressed the toxin production of C. difficile by replenishing proline consumed by it. Overall, the findings of the present study expand our understanding of the mechanisms by which probiotics inhibit C. difficile growth and contribute to the development of live biotherapeutic products based on molecular mechanisms for treating CDI.

PET: Parameter-efficient Knowledge Distillation on Transformer.

Given a large Transformer model, how can we obtain a small and computationally efficient model which maintains the performance of the original model? Transformer has shown significant performance improvements for many NLP tasks in recent years. However, their large size, expensive computational cost, and long inference time make it challenging to deploy them to resource-constrained devices. Existing Transformer compression methods mainly focus on reducing the size of the encoder ignoring the fact that the decoder takes the major portion of the long inference time. In this paper, we propose PET (Parameter-Efficient knowledge distillation on Transformer), an efficient Transformer compression method that reduces the size of both the encoder and decoder. In PET, we identify and exploit pairs of parameter groups for efficient weight sharing, and employ a warm-up process using a simplified task to increase the gain through Knowledge Distillation. Extensive experiments on five real-world datasets show that PET outperforms existing methods in machine translation tasks. Specifically, on the IWSLT'14 EN→DE task, PET reduces the memory usage by 81.20% and accelerates the inference speed by 45.15% compared to the uncompressed model, with a minor decrease in BLEU score of 0.27.

Investigation of metabolic crosstalk between host and pathogenic Clostridioides difficile via multiomics approaches.

Clostridioides difficile is a gram-positive anaerobic bacterium that causes antibiotic-associated infections in the gut. C. difficile infection develops in the intestine of a host with an imbalance of the intestinal microbiota and, in severe cases, can lead to toxic megacolon, intestinal perforation, and even death. Despite its severity and importance, however, the lack of a model to understand host-pathogen interactions and the lack of research results on host cell effects and response mechanisms under C. difficile infection remain limited. Here, we developed an in vitro anaerobic-aerobic C. difficile infection model that enables direct interaction between human gut epithelial cells and C. difficile through the Mimetic Intestinal Host-Microbe Interaction Coculture System. Additionally, an integrative multiomics approach was applied to investigate the biological changes and response mechanisms of host cells caused by C. difficile in the early stage of infection. The C. difficile infection model was validated through the induction of disaggregation of the actin filaments and disruption of the intestinal epithelial barrier as the toxin-mediated phenotypes following infection progression. In addition, an upregulation of stress-induced chaperones and an increase in the ubiquitin proteasomal pathway were identified in response to protein stress that occurred in the early stage of infection, and downregulation of proteins contained in the electron transfer chain and ATP synthase was observed. It has been demonstrated that host cell energy metabolism is inhibited through the glycolysis of Caco-2 cells and the reduction of metabolites belonging to the TCA cycle. Taken together, our C. difficile infection model suggests a new biological response pathway in the host cell induced by C. difficile during the early stage of infection at the molecular level under anaerobic-aerobic conditions. Therefore, this study has the potential to be applied to the development of future therapeutics through basic metabolic studies of C. difficile infection.

An Integrative Multiomics Approach to Characterize Prebiotic Inulin Effects on Faecalibacterium prausnitzii.

Faecalibacterium prausnitzii, a major commensal bacterium in the human gut, is well known for its anti-inflammatory effects, which improve host intestinal health. Although several studies have reported that inulin, a well-known prebiotic, increases the abundance of F. prausnitzii in the intestine, the mechanism underlying this effect remains unclear. In this study, we applied liquid chromatography tandem mass spectrometry (LC-MS/MS)-based multiomics approaches to identify biological and enzymatic mechanisms of F. prausnitzii involved in the selective digestion of inulin. First, to determine the preference for dietary carbohydrates, we compared the growth of F. prausnitzii in several carbon sources and observed selective growth in inulin. In addition, an LC-MS/MS-based intracellular proteomic and metabolic profiling was performed to determine the quantitative changes in specific proteins and metabolites of F. prausnitzii when grown on inulin. Interestingly, proteomic analysis revealed that the putative proteins involved in inulin-type fructan utilization by F. prausnitzii, particularly ß-fructosidase and amylosucrase were upregulated in the presence of inulin. To investigate the function of these proteins, we overexpressed bfrA and ams, genes encoding ß-fructosidase and amylosucrase, respectively, in Escherichia coli, and observed their ability to degrade fructan. In addition, the enzyme activity assay demonstrated that intracellular fructan hydrolases degrade the inulin-type fructans taken up by fructan ATP-binding cassette transporters. Furthermore, we showed that the fructose uptake activity of F. prausnitzii was enhanced by the fructose phosphotransferase system transporter when inulin was used as a carbon source. Intracellular metabolomic analysis indicated that F. prausnitzii could use fructose, the product of inulin-type fructan degradation, as an energy source for inulin utilization. Taken together, this study provided molecular insights regarding the metabolism of F. prauznitzii for inulin, which stimulates the growth and activity of the beneficial bacterium in the intestine.

An integrative multiomics approach to characterize anti-adipogenic and anti-lipogenic effects of Akkermansia muciniphila in adipocytes.

The cellular components of Akkermansia muciniphila are considered potential biotherapeutics for the improvement of obesity, diabetes, and metabolic diseases. However, the molecular-based mechanism of A. muciniphila for treatment of obesity, which can provide important evidence for human research, has rarely been explored. Here, we applied integrative multiomics approaches to investigate the underlying molecular mechanism involved in obesity treatment by A. muciniphila. First, the treatment with a cell lysate of A. muciniphila reduced lipid accumulation in 3T3-L1 cells and downregulated the mRNA expression of proteins involved in adipogenesis and lipogenesis. Our proteomic results revealed that A. muciniphila decreased the expression of proteins involved in fat cell differentiation, fatty acid metabolism, and energy metabolism in adipocytes. Moreover, A. muciniphila significantly reduced the level of metabolites related to glycolysis, the TCA cycle, and ATP in adipocytes. Interestingly, serine protease inhibitor A3 (SERPINA3) homologs were overexpressed in the 3T3-L1 cells treated with A. muciniphila. Small interfering RNA (siRNA) transfection demonstrated that A. muciniphila upregulates SERPINA3G expression and inhibits lipogenesis in adipocytes. Taken together, our multiomics-based approaches enabled to uncover the molecular mechanism of A. muciniphila for treatment of obesity and provide potent anti-lipogenic agents.

Development of an in vitro coculture device for the investigation of host-microbe interactions via integrative multiomics approaches.

The commensal gut bacterium Akkermansia muciniphila is well known as a promising probiotic candidate that improves host health and prevents diseases. However, the biological interaction of A. muciniphila with human gut epithelial cells has rarely been explored for use in biotherapeutics. Here, we developed an in vitro device that simulates the gut epithelium to elucidate the biological effects of living A. muciniphila via multiomics analysis: the Mimetic Intestinal Host-Microbe Interaction Coculture System (MIMICS). We demonstrated that both human intestinal epithelial cells (Caco-2) and the anaerobic bacterium A. muciniphila can remain viable for 12 h after coculture in the MIMICS. The transcriptomic and proteomic changes (cell-cell junctions, immune responses, and mucin secretion) in gut epithelial cells treated with A. muciniphila closely correspond with those reported in previous in vivo studies. In addition, our proteomic and metabolomic results revealed that A. muciniphila activates glucose and lipid metabolism in gut epithelial cells, leading to an increase in ATP production. This study suggests that A. muciniphila improves metabolism for ATP production in gut epithelial cells and that the MIMICS may be an effective general tool for evaluating the effects of anaerobic bacteria on gut epithelial cells.

Therapeutic Effects of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Combined with Cartilage Acellular Matrix Mediated Via Bone Morphogenic Protein 6 in a Rabbit Model of Articular Cruciate Ligament Transection.

Osteoarthritis (OA) is a general joint disease. Cartilage damage is associated with a decrease in the density of chondrocytes. Mesenchymal stem cells (MSCs) differentiate into adipocytes, osteocytes and chondrocytes, and are an excellent source of cell therapy. Cartilage-derived extracellular matrix (ECM) promotes chondrogenesis of MSCs. However, the role of MSCs stimulated by ECM is not well known in OA. The purpose of this study is to determine the role of specific factors generated by the application of ECM and umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs) in managing OA symptoms. Cartilage acellular matrix (CAM), which is a cartilage-derived ECM, was used to promote the chondrogenesis of UCB-MSCs. Induced MSCs were analyzed using chondrogenic markers (aggrecan, collagen type 2, and SOX9) and bone morphogenic protein 6 (BMP6). BMP6 is known to be involved in early chondrogenesis of MSCs. As a result, treatment with CAM significantly increased the expression of chondrogenic markers and BMP6 in UCB-MSCs. Treatment with recombinant human BMP6 also dramatically increased the levels of chondrogenic markers in UCB-MSCs. In addition, UCB-MSCs and CAM were used to evaluate OA symptom improvement in a rabbit articular cruciate ligament transection (ACLT) model. Application of UCB-MSCs and CAM enhanced not only the structure and synthesis of proteoglycan and collagen type 2 but also anti-inflammatory effects in both rabbit joint and synovial fluid. Moreover, the detection of human cells and involvement of BMP6 were confirmed in rabbit cartilage tissues. This study indicates that therapeutic potential of UCB-MSCs with CAM is mediated via BMP6 in OA.

Multi-omics based characterization of antibiotic response in clinical isogenic isolates of methicillin-susceptible/-resistant Staphylococcus aureus.

As demands for new antibiotics and strategies to control methicillin-resistant Staphylococcus aureus (MRSA) increase, there have been efforts to obtain more accurate and abundant information about the mechanism of the bacterial responses to antibiotics. However, most of the previous studies have investigated responses to antibiotics without considering the genetic differences between MRSA and methicillin-susceptible S. aureus (MSSA). Here, we initially applied a multi-omics approach into the clinical isolates (i.e., S. aureus WKZ-1 (MSSA) and S. aureus WKZ-2 (MRSA)) that are isogenic except for the mobile genetic element called staphylococcal cassette chromosome mec (SCCmec) type IV to explore the response to ß-lactam antibiotics (oxacillin). First, the isogenic pair showed a similar metabolism without oxacillin treatment. The quantitative proteomics demonstrated that proteins involved in peptidoglycan biosynthesis (MurZ, PBP2, SgtB, PrsA), two-component systems (VrsSR, WalR, SaeSR, AgrA), oxidative stress (MsrA1, MsrB), and stringent response (RelQ) were differentially regulated after the oxacillin treatment of the isogenic isolates. In addition, targeted metabolic profiling showed that metabolites belonging to the building blocks (lysine, glutamine, acetyl-CoA, UTP) of peptidoglycan biosynthesis machinery were specifically decreased in the oxacillin-treated MRSA. These results indicate that the difference in metabolism of this isogenic pair with oxacillin treatment could be caused only by SCCmec type IV. Understanding and investigating the antibiotic response at the molecular level can, therefore, provide insight into drug resistance mechanisms and new opportunities for antibiotics development.

Multi-omics characterization of the osmotic stress resistance and protease activities of the halophilic bacterium Pseudoalteromonas phenolica in response to salt stress.

The halophilic bacterium Pseudoalteromonas phenolica is well known as a promising candidate that enables the recycling of organic wastes at high salinity. However, for industrial applications of P. phenolica further research is required to explore the biological mechanism for maximizing the activities and productivities of this bacterium. In this study, we investigated the osmotic stress resistance and specific protease activities of P. phenolica in a normal-salt medium (0.3 M NaCl) and high-salt medium (1 M NaCl) based on intra- and extracellular multi-omics approaches. Proteins related to betaine and proline biosynthesis were increased under high salt stress. The targeted metabolite analysis found that proline was overproduced and accumulated outside the cell at high salinity, and betaine was accumulated in the cell by activation of biosynthesis as well as uptake. In addition, extracellular serine proteases were shown to be upregulated in response to salt stress by the extracellular proteomic analysis. The specific proteolytic activity assay indicated that the activities of serine proteases, useful enzymes for the recycling of organic wastes, were increased remarkably under high salt stress. Our results suggest that betaine and proline are key osmoprotectant metabolites of P. phenolica, and they can be used for the improvement of protease production and P. phenolica activities for the recycling of high-salt organic wastes in the future.

Non-clinical pharmacokinetic behavior of ginsenosides.

Ginsenosides, the major active ingredients of ginseng and other plants of the genus Panax, have been used as natural medicines in the East for a long time; in addition, their popularity in the West has increased owing to their various beneficial pharmacological effects. There is therefore a wealth of literature regarding the pharmacological effects of ginsenosides. In contrast, there are few comprehensive studies that investigate their pharmacokinetic behaviors. This is because ginseng contains the complicated mixture of herbal materials as well as thousands of constituents with complex chemical properties, and ginsenosides undergo multiple biotransformation processes after administration. This is a significant issue as pharmacokinetic studies provide crucial data regarding the efficacy and safety of compounds. Moreover, there have been many difficulties in the development of the optimal dosage regimens of ginsenosides and the evaluation of their interactions with other drugs. Therefore, this review details the pharmacokinetic properties and profiles of ginsenosides determined in various animal models administered through different routes of administration. Such information is valuable for designing specialized delivery systems and determining optimal dosing strategies for ginsenosides.

Therapeutic effect of long-interval repeated intravenous administration of human umbilical cord blood-derived mesenchymal stem cells in DBA/1 mice with collagen-induced arthritis.

Rheumatoid arthritis (RA) is a common inflammatory chronic disease. It has been reported that mesenchymal stem cells (MSCs) have the effect of immune suppression in collagen-induced arthritis (CIA) mice model. However, the in vivo therapeutic effect from the long-interval repeated intravenous administration of human umbilical cord blood-derived (hUCB)-MSCs had not been investigated in CIA mice model. This study was undertaken to investigate the effects of long-interval repeated intravenous administration of hUCB-MSCs at different doses in CIA mice model. Mice were intravenously injected with three different doses of hUCB-MSCs once every 2 weeks for three times. RA severity was assessed by clinical joint score and histologic analysis including hematoxylin and eosin staining, safranin-O staining, and toluidine blue staining. We used real-time polymerase chain reaction and flow cytometry to quantify differences in inflammatory cytokines and Tregs. Mice treated with hUCB-MSCs showed significant improvement in clinical joint score. Histologic analysis revealed that hUCB-MSCs definitely reduced joint inflammation, cartilage damage, and formation of pannus in multimedium and multihigh groups. These hUCB-MSCs also significantly decreased IL-1 beta protein levels in multimedium and multihigh groups and IL-6 protein levels in all hUCB-MSCs-treated groups. Furthermore, mRNA levels of IL-1 beta and IL-6 were decreased significantly in all hUCB-MSCs-treated groups, whereas the expression of anti-inflammatory cytokine IL-10 was increased in the multihigh group. Tregs known as suppressor T cells were also significantly increased in the multihigh group. Our findings suggest that long-interval repeated intravenous administration of hUCB-MSCs has therapeutic effects by improving symptoms of RA in CIA mice model in a dose-dependent manner.

Effect of fibroblast co-culture on the proliferation, viability and drug response of colon cancer cells.

Interactions between cancer cells and the surrounding fibroblasts serve an important role in cancer proliferation. Colon cancer co-culture model with colon fibroblasts and two metastatic models with lung and skin fibroblasts were established, and the co-culture effects on colon cancer cell proliferation, apoptosis and drug response were evaluated. Co-culture with CCD-18Co and BJ reduces SW480 cell proliferation by 4.2 and 5.3%, respectively, while WI-38 acts as a positive regulator and increases SW480 cell proliferation by 36%. CCD-18Co and BJ co-culture can also enhance XAV939 potency against SW480 cells by 16.8 and 27.3%; however, WI-38 co-culture reduces the effect of XAV939 by 38.2%. The present results suggest that, depending on fibroblast type, co-culture can have a positive/negative influence on colon cancer growth; therefore, care should be taken when considering fibroblasts as a target for future cancer therapies.

Location of the umbilicus in Korean women and its changes after breast reconstruction with an ipsilateral pedicled rectus abdominis musculocutaneous flap.

BACKGROUND: The umbilicus makes an important contribution to the natural appearance of the abdomen. To date, studies on its position in Korean women are lacking, and no standards have been established. The purpose of this study was to investigate the position of umbilicus in Korean women and to review changes in its position after ipsilateral pedicled rectus abdominis musculocutaneous (IP-RAM) flap. METHODS: This research consisted of two studies. In first study, 100 females who visited the emergency department with gastroenteritis between 2007 and 2011 were included. In second study, 40 women who underwent IP-RAM flap in the same period were included. Using abdominal computed tomography, we measured the distance between xiphoid process and umbilicus, represented by value a, and the distance between umbilicus and symphysis pubis, represented by value b. Thus, the location of the umbilicus was represented by the ratio a/b. The data were analyzed using Pearson correlation test and paired t-test. RESULTS: In study 1, the mean value of a/b was 1.07. Pearson correlation test revealed a significant correlation between age and a/b. In study 2, the mean value of a/b was 1.16 in preoperative measurements and 1.01 in postoperative measurements. The paired t-test showed a significant difference between preoperative and postoperative measurements, indicating cephalic migration of the umbilicus after surgery. CONCLUSIONS: The natural position of the umbilicus showed caudal migration with aging. Additionally, in a comparison of preoperative and postoperative measurements in patients who underwent IP-RAM flap, cephalic migration of the umbilicus was observed after surgery.

Micro-/nano-sized delivery systems of ginsenosides for improved systemic bioavailability.

Ginsenosides, dammarane-type triterpene saponins obtained from ginseng, have been used as a natural medicine for many years in the Orient due to their various pharmacological activities. However, the therapeutic potential of ginsenosides has been largely limited by the low bioavailability of the natural products caused mainly by low aqueous solubility, poor biomembrane permeability, instability in the gastrointestinal tract, and extensive metabolism in the body. To enhance the bioavailability of ginsenosides, diverse micro-/nano-sized delivery systems such as emulsions, polymeric particles, and vesicular systems have been investigated. The delivery systems improved the bioavailability of ginsenosides by enhancing solubility, permeability, and stability of the natural products. This mini-review aims to provide comprehensive information on the micro-/nano-sized delivery systems for increasing the bioavailability of ginsenosides, which may be helpful for designing better delivery systems to maximize the versatile therapeutic potential of ginsenosides.

Insulin-like growth factor binding protein-6 released from human mesenchymal stem cells confers neuronal protection through IGF-1R-mediated signaling.

Human bone marrow­derived mesenchymal stem cells (hMSCs) are a desirable cell source for cell­based therapy to treat nervous system injuries due to their ability to differentiate into specific cell types. In addition to their multipotency, hMSCs render the tissue microenvironment more favorable for tissue repair by secreting various growth factors. Our previous study demonstrated that hMSCs secrete several growth factors, including several insulin­like growth factor binding proteins (IGFBPs). Among these, IGFBP­6 binds with high affinity and inhibits insulin growth factor­2 (IGF­2) to inhibit the growth of IGF­2­dependent tumors. However, the function of IGFBP­6 in the nervous system remains to be fully elucidated. The present study investigated the protective effects of IGFBP­6 secreted by hMSCs on H2O2­injured primary cortical neuron cultures and lysolecithin­injured organotypic spinal cord slice cultures. Treatment of the H2O2­injured cortical neurons with conditioned media from hMSCs (hMSC­CM) increased the phosphorylation of Akt, reduced cell death and mitochondrial translocation of Bax, and regulated extracellular levels of IGF­1 and IGF­2. MTT assay, western blot analysis and ELISA were used to detect the cell viability and protein expression levels, respectively. An inhibitory antibody against IGFBP­6 eliminated this hMSC­CM­mediated neuroprotective effect in the injured cortical neuron cultures and spinal cord slice cultures. In addition, treatment with cyclolignan picropodophyllin, an inhibitor of IGF­1 receptor (IGF­1R), significantly inhibited neuronal protection by hMSC­CM. These findings demonstrated that hMSC­CM­mediated neuroprotection was attributed to IGF­1R­mediated signaling, potentiated via the inhibition of IGF­2 by IGFBP­6. The results of the present study provide insight into the mechanism by which hMSC administration may promote recovery from nerve injury.

Absorption Study of Genistein Using Solid Lipid Microparticles and Nanoparticles: Control of Oral Bioavailability by Particle Sizes.

In this study, the effect of particle size of genistein-loaded solid lipid particulate systems on drug dissolution behavior and oral bioavailability was investigated. Genistein-loaded solid lipid microparticles and nanoparticles were prepared with glyceryl palmitostearate. Except for the particle size, other properties of genistein-loaded solid lipid microparticles and nanoparticles such as particle composition and drug loading efficiency and amount were similarly controlled to mainly evaluate the effect of different particle sizes of the solid lipid particulate systems on drug dissolution behavior and oral bioavailability. The results showed that genistein-loaded solid lipid microparticles and nanoparticles exhibited a considerably increased drug dissolution rate compared to that of genistein bulk powder and suspension. The microparticles gradually released genistein as a function of time while the nanoparticles exhibited a biphasic drug release pattern, showing an initial burst drug release, followed by a sustained release. The oral bioavailability of genistein loaded in solid lipid microparticles and nanoparticles in rats was also significantly enhanced compared to that in bulk powders and the suspension. However, the bioavailability from the microparticles increased more than that from the nanoparticles mainly because the rapid drug dissolution rate and rapid absorption of genistein because of the large surface area of the genistein-solid lipid nanoparticles cleared the drug to a greater extent than the genistein-solid lipid microparticles did. Therefore, the findings of this study suggest that controlling the particle size of solid-lipid particulate systems at a micro-scale would be a promising strategy to increase the oral bioavailability of genistein.

Epigallocatechin-3-gallate prevents oxidative stress-induced cellular senescence in human mesenchymal stem cells via Nrf2.

Human mesenchymal stem cells (hMSCs) have great therapeutic potential due to their high plasticity, immune privileged status and ease of preparation, as well as a lack of ethical barriers to their use. However, their ultimate usefulness is limited by cellular senescence occurring secondary to increased cellular levels of reactive oxygen species (ROS) during their propagation in culture. The underlying molecular mechanisms responsible for this process in hMSCs remain unclear. An antioxidant polyphenol epigallocatechin-3-gallate (EGCG) found in green tea, is known to activate nuclear factor-erythroid 2-related factor 2 (Nrf2), a master transcriptional regulator of antioxidant genes. Herein, we examined the EGCG-mediated antioxidant mechanism in hMSCs exposed to ROS which involves Nrf2 activation. The H2O2-exposed hMSCs showed cellular senescence with significantly increased protein levels of acetyl-p53 and p21 in comparison with the untreated hMSCs, and these effects were prevented by pre-treatment with EGCG. By contrast, in Nrf2-knockdown hMSCs, EGCG lost its antioxidant effect, exhibiting high levels of acetyl-p53 and p21 following EGCG pre-treatment and H2O2 exposure. This indicates that Nrf2 and p53/p21 may be involved in the anti­senescent effect of EGCG in hMSCs. Taken together, these findings indicate the important role of EGCG in preventing oxidative stress-induced cellular senescence in hMSCs through Nrf2 activation, which has applications for the massive production of more suitable hMSCs for cell-based therapy.

Anti-proliferation effects of Cistanches salsa on the progression of benign prostatic hyperplasia.

Cistanche salsa has been used in traditional medicine for the treatment of kidney deficiency, neurasthenia, sexual dysfunction diseases, and benign prostatic hyperplasia (BPH). The aim of this study was to investigate the mechanism by which C. salsa extract (CSE) elicits an anti-proliferative effect on the prostate tissue of BPH-induced rats. The effects of CSE on BPH were evaluated in terms of prostate weight, production of serum dihydrotestosterone (DHT), and the mRNA expression of 5α-reductase type 1 and type 2 in the prostate tissue of BPH-induced rats. In addition, hematoxylin and eosin (H&E) staining was performed for histological examination of prostate gland morphology, and protein expression levels in prostate tissue were investigated by western blot analysis. CSE treatment decreased prostate weight, serum DHT concentration, and the mRNA expression of 5α-reductase type 1 and type 2 in prostate tissue of BPH-induced rats. In addition, CSE treatment suppressed cell proliferation by regulating the expression levels of inflammatory-related proteins (inducible nitric oxide synthase and cyclooxygenase 2) and apoptosis-associated proteins (caspase-3 and Bcl-2 family proteins). CSE may be a potential therapeutic candidate for BPH owing to its ability to regulate the expression of inflammatory and apoptosis-related proteins.

Vascular endothelial growth factor enhances axonal outgrowth in organotypic spinal cord slices via vascular endothelial growth factor receptor 1 and 2.

Enhancing adult nerve regeneration is a potential therapeutic strategy for treating spinal cord injury. Vascular endothelial growth factor (VEGF) is a major contributor to angiogenesis, which can reduce the spinal cord injury by inhibiting the inflammation and improve recovery after spinal cord injury. We have previously demonstrated that exogenous VEGF has neurotrophic effects on injured spinal nerves in organotypic spinal cord slice cultures. However, the mechanisms underlying the neurite growth by exogenous VEGF remain to be explored in spinal cord. In this study, we found out that exogenous VEGF mediated axonal outgrowth through VEGF receptor 1 (VEGFR1) and VEGFR2, both of which were expressed on organotypic spinal cord slices. Although VEGFR1 and VEGFR2 were constitutively expressed in some cells of control spinal cord slices, VEGF treatment upregulated expression of VEGFR1 and VEGFR2. Both VEGFR1 and VEGFR2 were expressed in neuronal cells as well as glial cells of organotypic spinal cord slices. We also observed that VEGF-induced axonal outgrowth was attenuated by a specific mitogen-activated protein kinase (MAPK) inhibitor PD98059 and a specific phosphoinositide 3-kinase (PI3K) inhibitor wortmannin. Thus, these findings suggest that these MAPK and PI3K pathways have important roles in regulating VEGF-induced axonal outgrowth in the postnatal spinal cord.

Effect of repetitive pecking at working length for glide path preparation using G-file.

OBJECTIVES: Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi) rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. MATERIALS AND METHODS: The G-file system (Micro-Mega) composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10). Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0) and 1 mm level (D1) under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05). RESULTS: The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05). CONCLUSIONS: Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO) size 20, without apical transportation at D0 level.