Amygdalin and exercise training exert a synergistic effect in improving cardiac performance and ameliorating cardiac inflammation and fibrosis in a rat model of myocardial infarction.

This study investigated the effects of amygdalin (AMY, a cyanogenic glycoside widely distributed in the fruits and seeds of Rosaceae plants) on cardiac performance and ventricular remodeling in a rat model of myocardial infarction (MI). We also investigated whether the combination of AMY with exercise training (ExT) has a beneficial synergistic effect in treating MI rats. MI was induced by the ligation of the left anterior descending coronary artery in male SD rats. ExT or AMY treatment was started 1 week after MI and continued for 1 week (short-term) or 8 weeks (long-term). Cardiac function was evaluated by echocardiographic and hemodynamic parameters. Heart tissues were harvested and subjected to 2,3,5-triphenyl-tetrazolium chloride, Masson's trichrome, hematoxylin-eosin, and immunohistochemical staining. Gene expression was determined by quantitative polymerase chain reaction. Western blot gave a qualitative assessment of protein levels. AMY or ExT improved cardiac function and reduced infarct size in MI rats. AMY or ExT also suppressed myocardial fibrosis and attenuated inflammation in the infarct border zone of hearts from MI rats, as evidenced by inhibition of collagen deposition, inflammatory cell infiltration, and pro-inflammatory markers (interleukin 1ß, interleukin 6, tumor necrosis factor-α, and cyclooxygenase 2). Notably, the effects of AMY combined with ExT were superior to those of AMY alone or ExT alone. Mechanistically, these beneficial functions were correlated with the inhibition of MI-induced activation of the transforming growth factor-ß/Smad pathway. Collectively, AMY and ExT exert a synergistic effect on improving cardiac performance and ameliorating cardiac inflammation and fibrosis after MI, and the effects of long-term intervention were better than short-term intervention.

MiR-30c-1-3p targets matrix metalloproteinase 9 involved in the rupture of abdominal aortic aneurysms.

Abdominal aortic aneurysm (AAA) can be fatal if ruptured, but there is no predictive biomarker. Our aim was to evaluate the prognostic potential of microRNAs (miRNAs/miRs) in an AAA mouse model and patients with unruptured AAA (URAAA) and ruptured AAA (RAAA). Among the 64 miRNAs differentially expressed in mice with AAA compared to control, miR-30c-1-3p, miR-432-3p, miR-3154, and miR-379-5p had high homology with human miRNAs. MiR-30c-1-3p plasma levels were significantly lower in patients with RAAA than in those with URAAA or control and tended to negatively correlate with the maximum aortic diameter (r = -0.3153, P = 0.06109). MiR-30c-1-3p targeted matrix metalloproteinase (MMP)-9 mRNA through the coding region and downregulated its expression in vitro. MMP-9 plasma concentrations were significantly higher in the RAAA group than in the URAAA group (P < 0.001) and were negatively associated with miR-30c-1-3p levels (r = -0.3671, P = 0.01981) and positively-with the maximal aortic diameter (r = 0.6251, P < 0.0001). The optimal cutoff values for MMP-9 expression and the maximal aortic diameter were 461.08 ng/ml and 55.95 mm, with areas under the curve of 0.816 and 0.844, respectively. Our results indicate that plasma levels of miR-30c-1-3p and MMP-9 may be candidate biomarkers of AAA progression. KEY MESSAGES: Downregulation of miR-30c-1-3p expression and upregulation of its potential target MMP-9 are predictors of the devastation of AAA. Downregulation of miR-30c-1-3p expression and its downstream impact on MMP-9 have a potential on predicting the development and rupture of AAA.

C2-C3 Anterior Cervical Diskectomy and Fusion for Hangman's Fractures with C2 Posterior Dislocation: Technical Notes.

BACKGROUND: The overwhelming majority of hangman's fractures cause anterior dislocation of C2. Hangman's fracture with C2 posterior dislocation is extremely rare; only 1 pediatric case was reported in 2018 to date. This kind of injury cannot be cataloged using current classification schemes, and no established treatment recommendations exist. The purpose of this article is to report a rare case of a hangman's fracture with C2 posterior dislocation, which does not fit into existing classification systems and discuss management technical notes to avoid pitfalls. METHODS: We describe this case, review relevant literature, and share our experience. RESULTS: A 31-year-old male sustained a hangman's fracture with C2 posterior dislocation after he fell into a 50-cm deep roadside ditch when riding a motorcycle. Radiograph and computed tomography on admission showed fractures through both pars of C2 and C2 posterior dislocation. Magnetic resonance imaging on admission showed high T2-weighted signal intensity of cervical spinal cord and compression of the cervical spinal cord by posterior dislocation of the C2 vertebral body. A C2-3 anterior cervical diskectomy and fusion was performed. At 6 months after operation, bony fusion was achieved and magnetic resonance imaging showed the T2-weighted signal hyperintensity of cervical spinal cord before surgery disappeared. CONCLUSIONS: C2-C3 anterior cervical diskectomy and fusion is recommended for hangman's fractures with C2 posterior dislocation. Traction before surgery is not recommended.

Exosomes derived from human umbilical cord mesenchymal stem cells alleviate acetaminophen-induced acute liver failure through activating ERK and IGF-1R/PI3K/AKT signaling pathway.

This study aimed to investigate the therapeutic potential of human umbilical cord mesenchymal stem cells derived exosomes (hUCMSC-Exo) in acute liver failure (ALF) in mice as well as its underlying mechanism. We found that a single tail vein administration of hucMSC-Exo effectively enhanced the survival rate, inhibited apoptosis in hepatocytes, and improved liver function in APAP-induced mouse model of ALF. Furthermore, the deletion of glutathione (GSH) and superoxide dismutase (SOD), generation of malondialdehyde (MDA), and the over production of cytochrome P450 E1 (CYP2E1) and 4-hydroxynonenal (4-HNE) caused by APAP were also inhibited by hucMSC-Exo, indicating that hucMSC-Exo inhibited APAP-induced apoptosis of hepatocytes by reducing oxidative stress. Moreover, hucMSC-Exo significantly down-regulated the levels of inflammatory cytokines IL-6, IL-1ß, and TNF-α in APAP-treated livers. Western blot showed that hucMSC-Exo significantly promoted the activation of ERK1/2 and IGF-1R/PI3K/AKT signaling pathways in APAP-injured LO2 cells, resulting in the inhibition of apoptosis of LO2 cells. Importantly, PI3K inhibitor LY294002 and ERK1/2 inhibitor PD98059 could reverse the function of hucMSC-Exo on APAP-injured LO2 cells in some extent. Our results suggest that hucMSC-Exo offer antioxidant hepatoprotection against APAP in vitro and in vivo by inhibitiing oxidative stress-induced apoptosis via upregulation of ERK1/2 and PI3K/AKT signaling pathways.

Bone marrow cells are differentiated into MDSCs by BCC-Ex through down-regulating the expression of CXCR4 and activating STAT3 signalling pathway.

Studies showed that the increase of myeloid-derived suppressor cells (MDSCs) in tumour microenvironment is closely related to the resistant treatment and poor prognosis of metastatic breast cancer. However, the effect of tumour-derived exosomes on MDSCs and its mechanism are not clear. Here, we reported that breast cancer cells (4T1)-secreted exosomes (BCC-Ex) were able to differentiate bone marrow cells into MDSCs and significantly inhibited the proliferation of T lymphocytes to provide an immunosuppressive microenvironment for cancer cells in vivo and in vitro. The number of MDSCs in bone marrow and spleen of 4T1 tumour-bearing mice and BCC-Ex infused mice was significantly higher than that of normal mice, whereas the number of T lymphocytes in spleen was significantly decreased. In addition, BCC-Ex markedly promoted the differentiation of MDSCs from bone marrow cells or bone marrow cells derived macrophages, seen as the increased expressions of MDSCs-related functional proteins Arginase-1 (Arg-1) and inducible nitric oxide synthase (iNOS). Furthermore, BCC-Ex significantly down-regulated the expressions of chemokine receptor CXCR4 and markedly up-regulated the levels of inflammatory cytokines IL-6 and IL-10 in bone marrow cells and macrophages and remarkably inhibited the division and proliferation of T cells. Importantly, CXCR4 agonist, CXCL12, could reverse the function of BCC-Ex, indicating that BCC-Ex-induced MDSCs might be dependent on the down-regulation of CXCR4. Western blot showed that BCC-Ex significantly promoted the phosphorylation of STAT3 in bone marrow cells, resulting in the inhibitions of the proliferation and apoptosis of bone marrow cells, and the aggravation of the differentiation of bone marrow cells into MDSCs.

Human amniotic mesenchymal stem cells inhibit hepatocellular carcinoma in tumour-bearing mice.

Hepatocellular carcinoma (HCC) is the third leading cause of the cancer-related death in the world. Human amniotic mesenchymal stem cells (hAMSCs) have been characterized with a pluripotency, low immunogenicity and no tumorigenicity. Especially, the immunosuppressive and anti-inflammatory effects of hAMSCs make them suitable for treating HCC. Here, we reported that hAMSCs administrated by intravenous injection significantly inhibited HCC through suppressing cell proliferation and inducing cell apoptosis in tumour-bearing mice with Hepg2 cells. Cell tracking experiments with GFP-labelled hAMSCs showed that the stem cells possessed the ability of migrating to the tumorigenic sites for suppressing tumour growth. Importantly, both hAMSCs and the conditional media (hAMSC-CM) have the similar antitumour effects in vitro, suggesting that hAMSCs-derived cytokines might be involved in their antitumour effects. Antibody array assay showed that hAMSCs highly expressed dickkopf-3 (DKK-3), dickkopf-1 (DKK-1) and insulin-like growth factor-binding protein 3 (IGFBP-3). Furthermore, the antitumour effects of hAMSCs were further confirmed by applications of the antibodies or the specific siRNAs of DKK-3, DKK-1 and IGFBP-3 in vitro. Mechanically, hAMSCs-derived DKK-3, DKK-1 and IGFBP-3 markedly inhibited cell proliferation and promoted apoptosis of Hepg2 cells through suppressing the Wnt/ß-catenin signalling pathway and IGF-1R-mediated PI3K/AKT signalling pathway, respectively. Taken together, our study demonstrated that hAMSCs possess significant antitumour effects in vivo and in vitro and might provide a novel strategy for HCC treatment clinically.

Role of craniofacial surgery in oral and maxillofacial tumors involving the skull base: A retrospective analysis of 126 patients.

OBJECTIVES: Oral and maxillofacial tumors involving the skull base (SB) are rare and complex, making treatment difficult and controversial. The purpose of the present study was to evaluate the treatment efficacy of craniofacial surgery (CFS). STUDY DESIGN: Patients who underwent CFS for these tumors between May 2000 and November 2017 were retrospectively analyzed. Clinicopathologic and treatment modality data were collected and follow-up was recorded. Kaplan-Meier and log-rank tests and Cox-regression model were used for survival analysis. RESULTS: In total, 126 patients were enrolled (70 males and 56 females; 97 malignant tumors). Squamous cell carcinoma accounted for the majority of tumors. The lip-submandibular-neck approach was most frequently applied. Through-and-through SB bone or partial dura resection was performed in 42 cases. A pathologic positive margin was found in 18 cases. Of the included patients, 80 underwent simultaneous craniofacial reconstruction. The postoperative complications rate was 11.1%. Estimated 1-year, 3-year, and 5-year overall survival rates were 78.8%, 68.2%, and 54.4% respectively; and the 1-year, 3-year, and 5-year recurrence-free survival rates were 77.4%, 66.8%, and 63.8%, respectively. Multivariate analysis indicated postoperative complications, radiotherapy, recurrence, and metastasis status had a negative impact on survival (P < .05). CONCLUSIONS: Although tumors involving the SB had various clinicopathologic characteristics, with interdisciplinary cooperation, CFS is an optimal option.

Human amniotic mesenchymal stem cells and their paracrine factors promote wound healing by inhibiting heat stress-induced skin cell apoptosis and enhancing their proliferation through activating PI3K/AKT signaling pathway.

BACKGROUND: Increasing evidence has shown that mesenchymal stem cells (MSCs) yield a favorable therapeutic benefit for thermal burn skin wounds. Human amniotic MSCs (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating skin wounds. However, the exact effects of hAMSCs on the healing of thermal burn skin wounds and their potential mechanisms are not explored. METHODS: hAMSCs were isolated from amniotic membrane and characterized by RT-PCR, flow cytometry, immunofluorescence, and tumorigenicity test. We assessed the effects of hAMSCs and hAMSC conditional medium (CM) on wound healing in a deep second-degree burn injury model of mice. We then investigated the biological effects of hAMSCs and hAMSC-CM on the apoptosis and proliferation of heat stress-injured human keratinocytes HaCAT and dermal fibroblasts (DFL) both in vivo and in vitro. Next, we explored the underlying mechanisms by assessing PI3K/AKT and GSK3ß/ß-catenin signaling pathways in heat injured HaCAT and DFL cells after hAMSCs and hAMSC-CM treatments using PI3K inhibitor LY294002 and ß-catenin inhibitor ICG001. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may activate PI3K/AKT signaling pathway. RESULTS: Our results showed that hAMSCs expressed various markers of embryonic stem cells and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAMSC and hAMSC-CM transplantation significantly promoted thermal burn wound healing by accelerating re-epithelialization with increased expression of CK19 and PCNA in vivo. hAMSCs and hAMSC-CM markedly inhibited heat stress-induced apoptosis in HaCAT and DFL cells in vitro through activation of PI3K/AKT signaling and promoted their proliferation by activating GSK3ß/ß-catenin signaling. Furthermore, we demonstrated that hAMSC-mediated activation of GSK3ß/ß-catenin signaling was dependent on PI3K/AKT signaling pathway. Antibody array assay showed that a panel of cytokines including PAI-1, C-GSF, periostin, and TIMP-1 delivered from hAMSCs may contribute to the improvement of the wound healing through activating PI3K/AKT signaling pathway. CONCLUSION: Our results demonstrated that hAMSCs and hAMSC-CM efficiently cure heat stress-induced skin injury by inhibiting apoptosis of skin cells and promoting their proliferation through activating PI3K/AKT signaling pathway, suggesting that hAMSCs and hAMSC-CM may provide an alternative therapeutic approach for the treatment of skin injury.

Human Menstrual Blood-Derived Stem Cells Inhibit the Proliferation of HeLa Cells via TGF-ß1-Mediated JNK/P21 Signaling Pathways.

Human menstrual blood-derived stem cells (hMBSCs) are a novel type of mesenchymal stem cells (MSCs) that have a high proliferative rate, multilineage differentiation potential, low immunogenicity, and low oncogenicity, making them suitable candidates for regenerative medicine. The therapeutic efficacy of hMBSCs has been demonstrated in some diseases; however, their effects on cervical cancer remain unclear. In the present study, we investigated whether hMBSCs have anticancer properties on cervical cancer cells in vivo and in vitro, which has not yet been reported. In vitro, transwell coculturing experiments revealed that hMBSCs suppress the proliferation and invasion of HeLa cervical cancer cells by inducing G0/G1 cell cycle arrest. In vivo, we established a xenografted BALB/c nude mouse model by subcutaneously coinjecting HeLa cells with hMBSCs for 21 days. We found that hMBSCs significantly decrease the average volume and average weight of xenografted tumors. ELISA, TGF-ß1 antibody, and recombinant human TGF-ß1 (rhTGF-ß1) were used to analyze whether TGF-ß1 contributed to cell cycle arrest. We found that hMBSC-secreted TGF-ß1 and rhTGF-ß1 induced cell cycle arrest and increased the expression of phospho-JNK and phospho-P21 in HeLa cells, which was mostly reversed by TGF-ß1 antibody. These results indicate that hMBSCs have antitumor properties on cervical cancer in vitro and in vivo, mediated by the TGF-ß1/JNK/p21 signaling pathway. In conclusion, this study suggests that hMBSC-based therapy is promising for the treatment of cervical cancer.

Enhancement of protein mechanical stability: Correlated deformations are handcuffed by ligand binding.

As revealed by previous experiments, protein mechanical stability can be effectively regulated by ligand binding with the binding site distant from the force-bearing region. However, the mechanism for such long-range allosteric control of protein mechanics is still largely unknown. In this work, we use protein topology-based elastic network model (ENM) and all-atomic steered molecular dynamics (SMD) simulations to study the impact of ligand binding on protein mechanical stability in two systems, i.e., GB1 and CheY-binding P2-domain of CheA (CBDCheA). Both ENM and SMD results show that the ligand binding has considerable and negligible effects on the mechanical stability of these two proteins, respectively. These results are consistent with the experimental observations. A physical mechanism for the enhancement of protein mechanical stability was then proposed: the correlated deformations of the force-bearing region and the binding site are handcuffed by the binding of ligand. The handcuff effect suppresses the propagation of internal force in the force-bearing region, thus improving the resistance to the loading force. Our study indicates that ENM method can effectively identify the structure motifs allosterically related to the deformation in the force bearing region, as well as the force propagation pathway within the structure of the studied proteins. Hence, it should be helpful to understand the molecular origin of the different mechanical properties in response to ligand binding for GB1 and CBDCheA.

Catalytic Conversion of Carbon Dioxide through C-N Bond Formation.

From the viewpoint of green chemistry and sustainable development, it is of great significance to synthesize chemicals from CO2 as C1 source through C-N bond formation. During the past several decade years, many studies on C-N bond formation reaction were involved, and many efforts have been made on the theory. Nevertheless, several great challenges such as thermodynamic limitation, low catalytic efficiency and selectivity, and high pressure etc. are still suffered. Herein, recent advances are highlighted on the development of catalytic methods for chemical fixation of CO2 to various chemicals through C-N bond formation. Meanwhile, the catalytic systems (metal and metal-free catalysis), strategies and catalytic mechanism are summarized and discussed in detail. Besides, this review also covers some novel synthetic strategies to urethanes based on amines and CO2. Finally, the regulatory strategies on functionalization of CO2 for N-methylation/N-formylation of amines with phenylsilane and heterogeneous catalysis N-methylation of amines with CO2 and H2 are emphasized.

Vesicles from the self-assembly of the ultra-small fatty acids with amino acids under aqueous conditions.

The properties of vesicles formed from the self-assembly of amphiphilic molecules can mimic the functionality of the natural lipid membranes. In this study, the self-assembly process of the amphiphilic structures formed by the interaction between ultra-small fatty acids [FAs, Cn (n = 4-8)] and amino acids (AAs) to generate vesicles under aqueous conditions were investigated in detail, along with the corresponding dynamic vesiculation mechanisms. Our results showed that the molar ratio of FAs/AAs and the chain length of FAs largely affected the structural characteristics and dispersion of vesicles. The detailed information about the entire size distributions and morphology of obtained vesicles were explored by the cryogenic transmission electron microscopy (Cryo-EM). Fourier transform infrared (FT-IR) spectra and quantum calculations suggested that the intermolecular hydrogen bond and electrostatic interactions between ultra-small molecules (FAs and AAs) during the aggregation processes were responsible for the formation of vesicles, where the hydrogen-bonding effect was dominant. Our findings shed new light on the effective and simple preparation of biological vesicles via ultra-small molecules self-assembly in aqueous solutions, which may have potential applications in vesicle physiology and drug delivery systems, and also get a mature understanding of the fundamental intermolecular interactions in life process.

Therapeutic efficiency of human amniotic epithelial stem cell-derived functional hepatocyte-like cells in mice with acute hepatic failure.

BACKGROUND: Hepatocyte transplantation has been proposed as an effective treatment for patients with acute liver failure (ALF), but its application is limited by a severe shortage of donor livers. Human pluripotent stem cells (hPSCs) have emerged as a potential cell source for regenerative medicine. Human amniotic epithelial stem cells (hAESCs) derived from amniotic membrane have multilineage differentiation potential which makes them suitable for possible application in hepatocyte regeneration and ALF treatment. METHODS: The pluripotent characteristics, immunogenicity, and tumorigenicity of hAESCs were studied by various methods. hAESCs were differentiated to hepatocyte-like cells (HLCs) using a non-transgenic and three-step induction protocol. ALB secretion, urea production, periodic acid-Schiff staining, and ICG uptake were performed to investigate the function of HLCs. The HLCs were transplanted into ALF NOD-SCID (nonobese diabetic severe combined immunodeficient) mouse, and the therapeutic effects were determined via liver function test, histopathology, and survival rate analysis. The ability of HLCs to engraft the damaged liver was evaluated by detecting the presence of GFP-positive cells. RESULTS: hAESCs expressed various markers of embryonic stem cells, epithelial stem cells, and mesenchymal stem cells and have low immunogenicity and no tumorigenicity. hAESC-derived hepatocytes possess the similar functions of human primary hepatocytes (hPH) such as producing urea, secreting ALB, uptaking ICG, storing glycogen, and expressing CYP enzymes. HLC transplantation via the tail vein could engraft in live parenchymal, improve the liver function, and protect hepatic injury from CCl4-induced ALF in mice. More importantly, HLC transplantation was able to significantly prolong the survival of ALF mouse. CONCLUSION: We have established a rapid and efficient differentiation protocol that is able to successfully generate ample functional HLCs from hAESCs, in which the liver injuries and death rate of CCl4-induced ALF mouse can be significantly rescued by HLC transplantation. Therefore, our results may offer a superior approach for treating ALF.

Does the Surgery-First Approach Produce Better Outcomes in Orthognathic Surgery? A Systematic Review and Meta-Analysis.

PURPOSE: The surgery-first approach (SFA) in orthognathic surgery, performed without presurgical orthodontic treatment, has gained attention, but the results remain controversial. The purpose of this study was to assess the current evidence on stability, efficacy, and surgical results of SFA versus conventional 3-stage method (CTM) orthognathic surgery. MATERIALS AND METHODS: A comprehensive search in PubMed and Web of Science was conducted. A systematic review and cumulative meta-analysis of all comparative studies were performed to assess the 2 strategies (SFA and CTM) using a random- or a fixed-effects model. Outcomes included treatment duration, postoperative stability, surgical movement, and postoperative occlusion. RESULTS: Ten nonrandomized controlled studies including 513 patients were identified. Compared with CTM, patients in the SFA group benefited from shorter total treatment duration (weighted mean difference [WMD], -5.25; 95% confidence interval [CI], -8.21 to -2.29; P = .0005), similar postoperative stability of the mandible (WMD, 0.35 mm; 95% CI, -0.24 to 0.94; P = .55) and maxilla (WMD, 0.13 mm; 95% CI, -0.35 to 0.60; P = .60), similar surgical movements, and other surgical results. CONCLUSIONS: SFA offers an efficient alternative to CTM with shorter total treatment duration, similar postoperative stability, and other surgical results but longer postoperative orthodontic time.

Xuebijing Injection () increases early survival rate by alleviating pulmonary vasopermeability in rats subjected to severe burns.

OBJECTIVE: To investigate the effects of Xuebijing Injection (, XBJ) on survival rate and pulmonary vasopermeability in a rat model of severe scald injury. METHODS: Rats were divided into two experiments: experiment 1 was monitored for 12 h post-injury for survival analysis after severe burns; in experiment 2, rats were killed for determination of pulmonary vascular permeability and pro-inflflammatory mediators. In both experiments, rats were subject to third-degree 50% total body surface area (TBSA) burns or sham injury followed by XBJ or normal saline (NS) treatment. In addition, rat pulmonary microvascular endothelium cells (PMECs) were pretreated with either XBJ or phosphate buffer saline (PBS), and then subjected to sham serum or scald serum stimulation for 2 or 6 h, followed by transwell examination for the permeability of PMECs. Meanwhile, pro-inflflammatory mediators in PMECs culture supernatant were also investigated. RESULTS: The average survival time in the scald+XBJ group was 582.1±21.2 min, which was signifificantly longer than that in the scald + NS group (345.8±25.4 min, P<0.01). Plasma levels of tumor necrosis factor-alpha (TNF-α), E-selectin, interleukin-6 (IL-6), vascular permeability and water content of lung tissues were signifificantly increased in animals after severe burns (P<0.01). However, administration of XBJ signifificantly decreased these levels in plasma and lung tissue. In in vitro cell experiments, XBJ markedly attenuated permeability in PMECs monolayer and reduced the levels of TNF-α, IL-6 and soluble E-selectin after stimulation with scald serum (P<0.01). CONCLUSIONS: XBJ increases early survival rate by alleviating pulmonary vasopermeability and inhibiting pro-inflflammatory mediators in rats subjected to lethal scald injury. XBJ may be a potent drug in treatment of severe burns.

Effects of ligand binding on the mechanical stability of protein GB1 studied by steered molecular dynamics simulation.

Regulation of the mechanical properties of proteins plays an important role in many biological processes, and sheds light on the design of biomaterials comprised of protein. At present, strategies to regulate protein mechanical stability focus mainly on direct modulation of the force-bearing region of the protein. Interestingly, the mechanical stability of GB1 can be significantly enhanced by the binding of Fc fragments of human IgG antibody, where the binding site is distant from the force-bearing region of the protein. The mechanism of this long-range allosteric control of protein mechanics is still elusive. In this work, the impact of ligand binding on the mechanical stability of GB1 was investigated using steered molecular dynamics simulation, and a mechanism underlying the enhanced protein mechanical stability is proposed. We found that the external force causes deformation of both force-bearing region and ligand binding site. In other words, there is a long-range coupling between these two regions. The binding of ligand restricts the distortion of the binding site and reduces the deformation of the force-bearing region through a long-range allosteric communication, which thus improves the overall mechanical stability of the protein. The simulation results are very consistent with previous experimental observations. Our studies thus provide atomic-level insights into the mechanical unfolding process of GB1, and explain the impact of ligand binding on the mechanical properties of the protein through long-range allosteric regulation, which should facilitate effective modulation of protein mechanical properties.

Preparation and evaluation of a novel liposome-based fluorescent probe for tumor imaging / 药学学报

In this study, a fluorescent nanoprobe based on liposome was synthesized by the hydrophobic interaction of phosphatidyl ethanolamine and indocyanine green (ICG). The nanoprobe was called LipoICG. In order to enhance the stability of liposome, we made a new LipoICG by coating it with human serum albumin (HSA). The new fluorescent nanoprobe, H-LipoICG, was produced for tumor imaging. The LipoICG and H-LipoICG were observed as spherical shape with uniform size distribution. The particle size of LipoICG was 94.47 nm, zeta potential was -43.5 mV and encapsulation efficiency (EE) was 81.5%. The particle size of H-LipoICG was 121.5 nm, zeta potential was -32.3 mV and EE was 98.2%. The coating of HSA could enhance the stability of liposome and increase the EE of ICG. Studies on drug release demonstrated that the release of ICG in H-LipoICG was slower than LipoICG, which suggests that HSA may reduce the ICG leakage from liposome, the fluorescence intensity could be enhanced in the nanoprobe. The Cell Counting Kit-8 assay demonstrated that LipoICG and H-LipoICG was not toxic for MCF-7 cells with good biocompatibility. In the study of biodistribution in mice, our experiments demonstrated that H-LipoICG had better tumor targeting ability and exhibited an enhanced fluorescence intensity than LipoICG. An optimize tumor contrast was observed after 8 h intravenous administration, the tumor margins could be clearly detected for up to 24 h after injection. So, H-LipoICG was an effective fluorescent probe for tumor imaging.

Dimethyl sulfoxide inhibits zymosan-induced intestinal inflammation and barrier dysfunction.

AIM: To investigate whether dimethyl sulfoxide (DMSO) inhibits gut inflammation and barrier dysfunction following zymosan-induced systemic inflammatory response syndrome and multiple organ dysfunction syndrome. METHODS: Sprague-Dawley rats were randomly divided into four groups: sham with administration of normal saline (SS group); sham with administration of DMSO (SD group); zymosan with administration of normal saline (ZS group); and zymosan with administration of DMSO (ZD group). Each group contained three subgroups according to 4 h, 8 h, and 24 h after surgery. At 4 h, 8 h, and 24 h after intraperitoneal injection of zymosan (750 mg/kg), the levels of intestinal inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-10] and oxides (myeloperoxidase, malonaldehyde, and superoxide dismutase) were examined. The levels of diamine oxidase (DAO) in plasma and intestinal mucosal blood flow (IMBF) were determined. Intestinal injury was also evaluated using an intestinal histological score and apoptosis of intestinal epithelial cells was determined by deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The intestinal epithelial tight junction protein, ZO-1, was observed by immunofluorescence. RESULTS: DMSO decreased TNF-α and increased IL-10 levels in the intestine compared with the ZS group at the corresponding time points. The activity of intestinal myeloperoxidase in the ZS group was higher than that in the ZD group 24 h after zymosan administration (P < 0.05). DMSO decreased the content of malondialdehyde (MDA) and increased the activity of superoxide dehydrogenase (SOD) 24 h after zymosan administration. The IMBF was lowest at 24 h and was 49.34% and 58.26% in the ZS group and ZD group, respectively (P < 0.05). DMSO alleviated injury in intestinal villi, and the gut injury score was significantly lower than the ZS group (3.6 ± 0.2 vs 4.2 ± 0.3, P < 0.05). DMSO decreased the level of DAO in plasma compared with the ZS group (65.1 ± 4.7 U/L vs 81.1 ± 5.0 U/L, P < 0.05). DMSO significantly preserved ZO-1 protein expression and localization 24 h after zymosan administration. The TUNEL analysis indicated that the number of apoptotic intestinal cells in the ZS group was much higher than the ZD group (P < 0.05). CONCLUSION: DMSO inhibited intestinal cytokines and protected against zymosan-induced gut barrier dysfunction.

MicroRNA-494 promotes cervical cancer proliferation through the regulation of PTEN.

The phosphoinositide 3-kinase (PI3K)/Akt signaling pathway appears to be a key regulator in cervical carcinogenesis. The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) protein is principally involved in the homeostatic maintenance of PI3K/Akt signaling and PTEN has been identified to play an important role in the occurrence and development of cervical cancer. MicroRNA (miRNA)-494 has been proven to be involved in the carcinogenesis and development of various types of cancer by directly targeting PTEN. However the role, mechanism and clinical significance of miR-494 in cervical cancer have not been further reported. In the present study, we analyzed the expression of miR-494 in -with PTEN expression and clinicopathological data of cervical cancer patients. The results showed that miR-494 expression was significantly upregulated in human cervical cancer cell lines and tissues. miR-494 upregulation was significantly associated with PTEN downregulation, adverse clinicopathological characteristics, poor overall and progression-free survival and poor prognosis. In vitro experiments showed that inhibition of miR-494 suppressed cell proliferation and growth by directly targeting the 3'-untranslated region (3'-UTR) of PTEN mRNA. These findings identified a novel molecular mechanism involved in the regulation of PTEN expression and cervical cancer progression. Results of the present study indicated that miR-494 may have an essential role in the carcinogenesis and progression of cervical cancer and targeting miR-494 may be a promising therapeutic strategy for the treatment of cervical cancer.