Cholecystokinin-like peptide mediates satiety by inhibiting sugar attraction.

Feeding is essential for animal survival and reproduction and is regulated by both internal states and external stimuli. However, little is known about how internal states influence the perception of external sensory cues that regulate feeding behavior. Here, we investigated the neuronal and molecular mechanisms behind nutritional state-mediated regulation of gustatory perception in control of feeding behavior in the brown planthopper and Drosophila. We found that feeding increases the expression of the cholecystokinin-like peptide, sulfakinin (SK), and the activity of a set of SK-expressing neurons. Starvation elevates the transcription of the sugar receptor Gr64f and SK negatively regulates the expression of Gr64f in both insects. Interestingly, we found that one of the two known SK receptors, CCKLR-17D3, is expressed by some of Gr64f-expressing neurons in the proboscis and proleg tarsi. Thus, we have identified SK as a neuropeptide signal in a neuronal circuitry that responds to food intake, and regulates feeding behavior by diminishing gustatory receptor gene expression and activity of sweet sensing GRNs. Our findings demonstrate one nutritional state-dependent pathway that modulates sweet perception and thereby feeding behavior, but our experiments cannot exclude further parallel pathways. Importantly, we show that the underlying mechanisms are conserved in the two distantly related insect species.

[Effect of Huanglian Jiedu Decoction on TREM2/Akt/GSK3ß pathway in cerebral cortex of APP/PS1 transgenic mice].

The Chinese medical mechanism of Huanglian Jieduo Decoction on treating Alzheimer's disease(AD) characterized by "toxin damaging brain collateral" is still unclear. This study aims to explore the mechanism of Huanglian Jieduo Decoction on regulating triggering receptor expressed on myeloid cells 2(TREM2)/protein kinase B(Akt)/glycogen synthase kinase 3ß(GSK3ß) pathway to improve the cognitive deficit in APP/PS1 transgenic mice. APP/PS1 mice of approximately nine months old were randomly divided into the model group, the low, medium, and high(2.5, 5, and 10 g·kg~(-1)) groups of Huanglian Jiedu Decoction, and 0.75 mg·kg~(-1) donepezil hydrochloride group, and the C57BL/6J mice with the same age were taken as the normal group. After one month of continuous oral administration, a Morris water maze was performed to detect the learning and memory ability of mice. Hematoxylin-eosin(HE) staining was applied to observe the morphology of neuronal cells in the cortical area of mice. Immunofluorescence was used to detect the protein expressions of ß-amyloid(Aß_(1-42)), CD86, and arginase 1(Arg1). The mRNA levels of interleukin(IL)-1ß, IL-6, and IL-10 in the cortex of mice were detected by real-time fluorescence quantitative polymerase chain reaction(RT-qPCR). The protein expressions of TREM2, phosphoinositide-3 kinase(PI3K), Akt, GSK3ß, and beta-catenin(ß-catenin) in mouse cortex were determined by Western blot. The results indicated that the escape latency of the model group was significantly prolonged, and the residence time in the target quadrant and the number of crossing the platform were significantly reduced compared with the normal group. Mice in the model group had a significantly lower number of neurons in the cortex and showed nuclear pyknosis and a significant increase in the expressions of Aß_(1-42) and CD86. The mRNA levels of IL-1ß and IL-6 in tissue were significantly increased, IL-10 were increased, while Arg1 were significantly decreased. The expression of TREM2, p-PI3K(Y607), p-Akt(T308), p-GSK3ß(Ser9), and ß-catenin in the cortex were significantly down-regulated. Compared with the model group, the escape latency of the mice in the administration group was significantly shortened, and the number of crossing the platform and the residence time in the target quadrant were significantly increased. Furthermore, the number of neurons in the cortex of mice was increased, and nuclear pyknosis was improved. Aß_(1-42) deposition was decreased significantly. The mRNA levels of IL-1ß, IL-6 and CD86 were significantly decreased, while IL-10 and Arg1 levels were significantly increased. The expression of TREM2, p-PI3K(Y607), p-Akt(T308), p-GSK3ß(Ser9), and ß-catenin protein in the cortex of each administration group was significantly up-regulated compared with the model group. In conclusion, Huanglian Jiedu Decoction reduced the expression of Aß_(1-42) and neuroinflammation to a neuro-protective effect, thereby improving the learning and memory ability in APP/PS1 mice, which may be related to the TREM2/Akt/GSK3ß signaling pathway.

Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov., isolated from coastal sediment.

Two novel rod-shaped, Gram-stain-negative, aerobic and non-motile bacterial strains, designated M39T and C2-7T, were isolated from the coastal sediment of Xiaoshi Island, Weihai, PR China. Growth of strain M39T occurred at 15-37 °C, at pH 6.0-9.0 and in the presence of 1.0-9.0 % (w/v) NaCl. Strain C2-7T grew at 15-40 °C, at pH 6.0-8.0 and in the presence of 0.5-8.0 % (w/v) NaCl. Phylogenetic analysis based 16S rRNA gene sequences revealed that strains M39T and C2-7T belong to the phylum Bacteroidota. Based on the results of 16S rRNA gene sequence analysis, the closest relative of strain M39T was Robiginitalea marina KCTC 92035T (95.4 %), and the closest relative of strain C2-7T was Algoriphagus namhaensis DPG-3T (97.0 %). The percentage of conserved protein and average nucleotide identity values between strain M39T and some species of the genus Robiginitalea were 66.9-77.6% and 69.3-71.0 %, respectively, while those between strain C2-7T and some species of the genus Algoriphagus were 68.0-70.1% and 56.1-72.6 %, respectively. The major cellular fatty acids (>10 %) of strain M39T consisted of iso-C15 : 1 F, iso-C15 : 0 and iso-C17 : 0 3-OH, while those of strain C2-7T were iso-C15 : 0 and C16 : 1 ω7c/C16 : 1 ω6c. MK-6 was the only respiratory quinone that was compatible with the genus of strain M39T. The predominant menaquinone of strain C2-7T was MK-7. The major polar lipids of strain M39T were phosphatidylethanolamine and glycolipids, and those of strain C2-7T were phosphatidylethanolamine, one unidentified aminolipid and four unidentified lipids. The DNA G+C contents of strains M39T and C2-7T were 46.9 and 40.8 mol%, respectively. Based upon the results presented in this study, strains M39T and C2-7T represent novel species of the genera Robiginitalea and Algoriphagus, respectively, for which the names Robiginitalea aurantiaca sp. nov. and Algoriphagus sediminis sp. nov. are proposed with the type strains M39T (=MCCC 1H00498T=KCTC 92014T) and C2-7T (=MCCC 1H00414T=KCTC 92027T).

Winogradskyella vincentii sp. nov. and Winogradskyella alexanderae sp. nov., two novel bacteria isolated from intertidal sediment.

Two novel Gram-stain-negative, facultative anaerobic, chemoheterotrophic, non-motile and rod-shaped strains were isolated from intertidal sediment sampled at Xiaoshi Island, Weihai, PR China. Full sequence analysis of the 16S rRNA genes showed that the two strains were closely related to members of the genus Winogradskyella and the phylogenetic similarities to their closest relative, Winogradskyella aquimaris, were 96.7 and 95.8 %, respectively. The DNA G+C contents of strains 2Y89T and D23T were 33.3 and 35.1 mol%, respectively. The respiratory quinone detected in both strains was MK-6. The major fatty acids detected in strain 2Y89T were iso-C15 : 0 and iso-C15 : 1G, and in strain D23T they were iso-C15 : 1G, iso-C15 : 0 and iso-C17 : 03-OH. The principal polar lipids of strain 2Y89T mainly included phosphatidylethanolamine, aminoglycolipids, unidentified aminolipids, unidentified glycolipids and unidentified lipids; strain D23T was the same as strain 2Y89T except that it did not contain aminoglycolipids. Based on the phenotypic, chemical taxonomic, genotypic and phylogenetic features established in this study, we suggest that the new strains represent two novel species of the genus Winogradskyella, for which the names Winogradskyella vincentii sp. nov. (type strain 2Y89T=MCCC 1H00477T=KCTC 92034T) and Winogradskyella alexanderae sp. nov. (type strain D23T=MCCC 1H00462T=KCTC 92023T) are proposed.

Incidence and risk factors for postoperative venous thromboembolism in patients with ovarian cancer: Systematic review and meta-analysis.

BACKGROUND: Venous Thromboembolism (VTE) is a leading cause of morbidity and mortality in patients with ovarian malignancy. There is no meta-analysis available on this topic so far. The aim of our study was to quantitatively synthesize the data from studies with respect to the incidence and risk factors for postoperative VTE among cases with epithelial ovarian cancer (EOC). METHODS: PubMed, Web of Science, and Embase were searched for papers containing the key words "venous thromboembolism", "postoperative", "postoperation", "ovarian neoplasm", "ovary neoplasm", "ovarian cancer", "ovary cancer", and "cancer of ovary". Studies selection, data extraction, quality assessment of eligible studies were performed independently by our different reviewers. Meta-analyses were conducted to determine postoperative VTE incidence and risk factors in women with EOC. Sensitivity analysis were used to verify the robustness of the results of meta-analyses if necessary. RESULTS: In total, 19 studies were included in this meta-analysis. The pooled incidence for postoperative symptomatic VTE was 3% (95% CI, 0.03-0.04) and for postoperative symptomatic as well as asymptomatic VTE was 8% (95% CI, 0.07-0.09). The presence of history of VTE (OR, 2.37), advanced-stages (OR, 2.35), high complexity of surgery (OR, 2.20), clear cell carcinoma of ovary (OR, 2.53) and residual disease>1 cm (OR, 2.57) significantly increase the likelihood of having postoperative VTE. Other risk factors for postoperative VTE in EOC patients were BMI>30 (OR, 1.58), per 10-years increase in age (OR, 1.22), ASA score>2 (OR, 1.45), ascites (OR, 2.07), the diameter of residual disease is between 0 cm to 1 cm (OR, 2.06) and smoking history (OR, 1.54). CONCLUSIONS: This study revealed that VTE, especially subclinical VTE, is a prevalent complication in postoperative patients with EOC. History of VTE, advanced FIGO stages, high complexity of surgery, obesity, older age, ascites, higher ASA score, smoking history and suboptimal debulking are associated with this increased incidence of postoperative VTE among patients with EOC. PROSPERO registration number: CRD42020209662.

Effects of temperature and ion channel blocks on propagation of action potential in myelinated axons.

Potassium ion and sodium ion channels play important roles in the propagation of action potentials along a myelinated axon. The random opening and closing of ion channels can cause the fluctuation of action potentials. In this paper, an improved Hodgkin-Huxley chain network model is proposed to study the effects of ion channel blocks, temperature, and ion channel noise on the propagation of action potentials along the myelinated axon. It is found that the chain network has minimum coupling intensity threshold and maximum tolerance temperature threshold that allow the action potentials to pass along the whole axon, and the blockage of ion channels can change these two thresholds. A striking result is that the simulated value of the optimum membrane size (inversely proportional to noise intensity) coincides with the area range of feline thalamocortical relay cells in biological experiments.

A computational study of Tat-CDK9-Cyclin binding dynamics and its implication in transcription-dependent HIV latency.

HIV is a virus that attacks the T cells. HIV may either actively replicate or become latent within host cells for years. Since HIV uses its own protein Tat to hijack the host CDK9-Cyclin complex for transcription, Tat is implicated in transcription-dependent HIV latency. To quantify the impact of Tat binding, we propose a computational framework to probe the dynamics of the CDK9-Cyclin interface and the ATP pocket reorganization upon binding by different Tat mutants. Specifically, we focus on mutations at three Tat residues P10, W11, and N12 that are known to interact directly with CDK9 based on the crystal structure of the Tat-CDK9-Cyclin complex. Our molecular dynamics simulations show that the CDK9-Cyclin interface becomes slightly weaker for P10S and W11R mutants but tighter for the K12N mutant. Furthermore, the side chain orientation of residue K48 in the ATP pocket of CDK9 is similar to the inactive state in P10S and W11R simulations, but similar to the active state in K12N simulations. These are consistent with some existing but puzzling observations of latency for these mutants. This framework may hence help gain a better understanding of the role of Tat in the transcription-dependent HIV latency establishment.

Pymetrozine inhibits reproductive behavior of brown planthopper Nilaparvata lugens and fruit fly Drosophila melanogaster.

Pymetrozine is a promising chemical used to control brown planthopper, which developed resistance to imidacloprid and buprofezin in the past decade. Field efficacy indicates that pymetrozine can reduce the number of offsprings of brown planthopper, but the specific physiological mechanism is unknown. In this study, we systematically described the mating process of brown planthopper including 8 steps (abdominal vibration, following, positioning, wing extension, attempted copulation, copulation, terminated copulation and leaving) and explored the optimal mating time after adult eclosion (3-5 days) and observation time (30 mins). Also, behavioral data showed that pymetrozine can affect the mating behavior and female fecundity of brown planthopper and fruit fly. As one of the target genes for pymetrozine, Nanchung (Nan), the nan36a mutant male courtship index, female receptivity and the number of offsprings were significantly decreased. Behavioral defects in nan36a mutant flies can be rescued by expressed NlNan. Our results indicated that Nan plays essential roles in the mating behavior and female fecundity. These findings provide useful information for demonstrating that pymetrozine effectively reduce the reproduction of brown planthopper and contribute to our understanding of reproductive strategies controlled by pymetrozine in insects.

HKPocket: human kinase pocket database for drug design.

BACKGROUND: The kinase pocket structural information is important for drug discovery targeting cancer or other diseases. Although some kinase sequence, structure or drug databases have been developed, the databases cannot be directly used in the kinase drug study. Therefore, a comprehensive database of human kinase protein pockets is urgently needed to be developed. RESULTS: Here, we have developed HKPocket, a comprehensive Human Kinase Pocket database. This database provides sequence, structure, hydrophilic-hydrophobic, critical interactions, and druggability information including 1717 pockets from 255 kinases. We further divided these pockets into 91 pocket clusters using structural and position features in each kinase group. The pocket structural information would be useful for preliminary drug screening. Then, the potential drugs can be further selected and optimized by analyzing the sequence conservation, critical interactions, and hydrophobicity of identified drug pockets. HKPocket also provides online visualization and pse files of all identified pockets. CONCLUSION: The HKPocket database would be helpful for drug screening and optimization. Besides, drugs targeting the non-catalytic pockets would cause fewer side effects. HKPocket is available at http://zhaoserver.com.cn/HKPocket/HKPocket.html.

Metabolomics analysis of Pulsatilla decoction on treatment of wetness-heat-induced diarrhea in rats based on UPLC-Q/TOF-MS/MS.

Pulsatilla decoction (PD) is a classical prescription in traditional Chinese medicine that has therapeutic effects on wetness-heat-induced diarrhea (WHD). To investigate the therapeutic effects of PD in the treatment of WHD and elucidate the potential mechanism, we used a metabolomics strategy on the base of ultraperformance liquid chromatography coupled with quadrupole time-of-flight/mass spectrometry (UPLC-Q/TOF-MS/MS) and analyzed the serum samples of 32 rats to identify differential metabolites and pathways associated with the PD treatment of WHD. With variable importance for projection >1.0 in the Orthogonal partial least-squares discriminant analysis (OPLS-DA ) models and FC ≥1.2 or ≤0.8, 67 differential metabolites in the model and control groups and 33 differential metabolites in the model and PD groups were screened. A total of 23 differential metabolites were selected based on Venny analysis. Functional analysis showed that the differential metabolites identified were primarily involved in pentose and glucuronate interconversions, glycerophospholipid metabolism, tryptophan metabolism, starch and sucrose metabolism, and glycerolipid metabolism. This study suggested that PD exerts inhibitory effects on WHD. In particular, the significant roles of PD for treating WHD lie in regulating perturbed energy metabolism, glycerophospholipid metabolism and glycerolipid metabolism, and promoting lysoPC production restoring the function of intestinal tract.

Pymetrozine activates TRPV channels of brown planthopper Nilaparvata lugens.

The commercial insecticide pymetrozine has been extensively used for brown planthopper control in East Asia. The transient receptor potential vanilloid (TRPV) channel, which consists of two proteins, Nanchung (Nan) and Inactive (Iav), has recently been shown to be the molecular target of pymetrozine in the fruit fly (Drosophila melanogaster) and pea aphid (Acyrthosiphon pisum). In this study, we characterized the Nan and Iav TRPV channel subunits of N. lugens and measured the action of pymetrozine on them. NlNan and NlIav are structurally similar to homologs from other insects. The expression pattern analysis of various body parts showed that NlNan and NlIav were both more abundantly expressed in antennae. When NlNan and NlIav were co-expressed in Xenopus laevis oocytes, they formed channels with high sensitivity to pymetrozine (EC50 = 5.5 × 10-8 M). Behavioral observation revealed that the gravitaxis defect in the fruit fly nan36a mutant was rescued by ectopically expressed NlNan and the rescued behavior could be abolished by pymetrozine. Our results confirm that NlNan and NlIav co-expressed complexes can be activated by pymetrozine both in vitro and in vivo and provide useful information for future resistance mechanism studies.

Protein structure prediction.

Predicting 3D structure of protein from its amino acid sequence is one of the most important unsolved problems in biophysics and computational biology. This paper attempts to give a comprehensive introduction of the most recent effort and progress on protein structure prediction. Following the general flowchart of structure prediction, related concepts and methods are presented and discussed. Moreover, brief introductions are made to several widely-used prediction methods and the community-wide critical assessment of protein structure prediction (CASP) experiments.

3DRobot: automated generation of diverse and well-packed protein structure decoys.

MOTIVATION: Computationally generated non-native protein structure conformations (or decoys) are often used for designing protein folding simulation methods and force fields. However, almost all the decoy sets currently used in literature suffer from uneven root mean square deviation (RMSD) distribution with bias to non-protein like hydrogen-bonding and compactness patterns. Meanwhile, most protein decoy sets are pre-calculated and there is a lack of methods for automated generation of high-quality decoys for any target proteins. RESULTS: We developed a new algorithm, 3DRobot, to create protein structure decoys by free fragment assembly with enhanced hydrogen-bonding and compactness interactions. The method was benchmarked with three widely used decoy sets from ab initio folding and comparative modeling simulations. The decoys generated by 3DRobot are shown to have significantly enhanced diversity and evenness with a continuous distribution in the RMSD space. The new energy terms introduced in 3DRobot improve the hydrogen-bonding network and compactness of decoys, which eliminates the possibility of native structure recognition by trivial potentials. Algorithms that can automatically create such diverse and well-packed non-native conformations from any protein structure should have a broad impact on the development of advanced protein force field and folding simulation methods. AVAILIABLITY AND IMPLEMENTATION: http://zhanglab.ccmb.med.umich.edu/3DRobot/ CONTACT: jiay@phy.ccnu.edu.cn; zhng@umich.edu SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Oxyresveratrol, a Stilbene Compound from Morus alba L. Twig Extract Active Against Trichophyton rubrum.

Morus alba L. (mulberry) twig is known to have an inhibitory effect on pathogens in traditional Chinese medicine. In the present study, the dermophytic fungus, Trichophyton rubrum, was used to evaluate the inhibitory effect of total M. alba twig extract and extracts obtained using solvents with different polarities by the method of 96-well MTT colorimetry. The main active substance was isolated and identified by tracking its activity. In addition, the inhibitory effects of active extracts and a single active substance were investigated in combination with miconazole nitrate. Our data indicated that ethyl acetate extracts of mulberry twig (TEE) exhibited a desired inhibitory activity on T. rubrum with the minimum inhibitory concentration (MIC) of 1.000 mg/mL. With activity tracking, the main substance showing antimicrobial activity was oxyresveratrol (OXY), which was isolated from TEE. Its MIC for inhibiting the growth of T. rubrum was 0.500 mg/mL. The combined use of miconazole nitrate and OXY showed a synergistic inhibitory effect, as shown by a significant decrease in the MIC of both components. Based on the OXY content in TEE, the contribution rate of OXY to the inhibitory effect of TEE on T. rubrum was 80.52%, so it was determined to be the main antimicrobial substance in M. alba twig. Copyright © 2017 John Wiley & Sons, Ltd.

A Network of Conformational Transitions Revealed by Molecular Dynamics Simulations of the Binary Complex of Escherichia coli 6-Hydroxymethyl-7,8-dihydropterin Pyrophosphokinase with MgATP.

6-Hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) catalyzes the first reaction in the folate biosynthetic pathway. Comparison of its X-ray and nuclear magnetic resonance structures suggests that the enzyme undergoes significant conformational change upon binding to its substrates, especially in three catalytic loops. Experimental research has shown that, in its binary form, even bound by analogues of MgATP, loops 2 and 3 remain rather flexible; this raises questions about the putative large-scale induced-fit conformational change of the HPPK-MgATP binary complex. In this work, long-time all-atomic molecular dynamics simulations were conducted to investigate the loop dynamics in this complex. Our simulations show that, with loop 3 closed, multiple conformations of loop 2, including the open, semiopen, and closed forms, are all accessible to the binary complex. These results provide valuable structural insights into the details of conformational changes upon 6-hydroxymethyl-7,8-dihydropterin (HP) binding and biological activities of HPPK. Conformational network analysis and principal component analysis related to the loops are also discussed.

MicroRNA-125b attenuates epithelial-mesenchymal transitions and targets stem-like liver cancer cells through small mothers against decapentaplegic 2 and 4.

UNLABELLED: Emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) play important roles in tumor metastasis and recurrence. Understanding molecular mechanisms that regulate the EMT process is crucial for improving treatment of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) play important roles in HCC; however, the mechanisms by which miRNAs target the EMT and their therapeutic potential remains largely unknown. To better explore the roles of miRNAs in the EMT process, we established an EMT model in HCC cells by transforming growth factor beta 1 treatment and found that several tumor-related miRNAs were significantly decreased. Among these miRNAs, miR-125b expression was most strongly suppressed. We also found down-regulation of miR-125b in most HCC cells and clinical specimens, which correlated with cellular differentiation in HCC patients. We then demonstrated that miR-125b overexpression attenuated EMT phenotype in HCC cancer cells, whereas knockdown of miR-125b promoted the EMT phenotype in vitro and in vivo. Moreover, we found that miR-125b attenuated EMT-associated traits, including chemoresistance, migration, and stemness in HCC cells, and negatively correlated with EMT and cancer stem cell (CSC) marker expressions in HCC specimens. miR-125b overexpression could inhibit CSC generation and decrease tumor incidence in the mouse xenograft model. Mechanistically, our data revealed that miR-125b suppressed EMT and EMT-associated traits of HCC cells by targeting small mothers against decapentaplegic (SMAD)2 and 4. Most important, the therapeutic delivery of synthetic miR-125b mimics decreased the target molecule of CSC and inhibited metastasis in the mice model. These findings suggest a potential therapeutic treatment of miR-125b for liver cancer. CONCLUSION: miR-125b exerts inhibitory effects on EMT and EMT-associated traits in HCC by SMAD2 and 4. Ectopic expression of miR-125b provides a promising strategy to treat HCC.

Stimulation of Nitric Oxide Production Contributes to the Antithrombotic Effect of Stromal Cell-Derived Factor-1α in Preventing Microsurgical Anastomotic Thrombosis.

Background Intimal injury plays a critical role in initiating the pathogenesis of thrombosis formation after microsurgical anastomosis. Application of stromal cell-derived factor-1α (SDF-1α) is reported to promote early regeneration of injured intima through migration of endothelial cells and mobilization of endothelial progenitor cells. We therefore hypothesized that local transfer of SDF-1α gene would inhibit microsurgical anastomotic thrombosis. Methods Sixty Sprague-Dawley rats were used and divided randomly into three groups (SDF-1α group, plasmid group, and saline group) in this study. Plasmid DNA encoding SDF-1α, empty plasmid, and saline were injected into the left femoral muscles of rats from each group, respectively. Seven days after injection, peripheral blood samples were obtained to measure the plasma levels of SDF-1α and nitric oxide (NO). The left femoral artery of each rat was crushed, transected, and repaired by end-to-end microsurgical anastomosis. Vascular patency was assessed at 15, 30, and 120 minutes after reperfusion using milk test. Thrombosis formation was assessed with hematoxylin and eosin staining and scanning electron microscopy at 120 minutes postoperatively. Results The plasma levels of SDF-1α and NO in SDF-1α group were significantly higher than those in plasmid group and saline group (p < 0.01). The patency rate in SDF-1α group was significantly higher than that in control groups at 120 minutes after reperfusion (p < 0.05). Treatment of SDF-1α significantly reduced the size of thrombotic occlusion when compared with controls (p < 0.05). All SDF-1α recipients exhibited decreased thrombosis under scanning electron microscopy. Conclusions The current study demonstrated that local transfer of SDF-1α gene increases arterial patency and inhibits microsurgical anastomotic thrombosis in a crush model of femoral artery in rat. The antithrombotic effect of SDF-1α may be mediated through increased production of endogenous NO. These findings provide a novel approach for inhibition of microsurgical anastomotic thrombosis.

Combined Anterolateral Thigh and Anteromedial Thigh Flap for Extensive Extremity Reconstruction: Vascular Anatomy and Clinical Application.

BACKGROUND: The combined anterolateral thigh (ALT) and anteromedial thigh (AMT) flap has been previously reported for use in complicated head and neck reconstruction. However, it has not gained popularity due to the vascular variation. Here, we explore the vascular basis of this combined flap, and report its application in extremity reconstruction. METHODS: This study was divided into two parts: vascular anatomy and clinical application. In the anatomical study, 52 sides of adult thighs were dissected to identity vascular perforators supplying the combined ALT and AMT flap, with focus on sizeable perforators (larger than 0.5 mm) arising from the descending branch of the lateral circumflex femoral artery.Clinically, five male patients were treated by combined ALT and AMT flaps for extensive extremity reconstruction from January 2006 to December 2010. The mean age was 32 years (range, 23-45 years). The combined flap was used for covering large soft-tissue defects in forearm (n = 3) and calf (n = 2). For each patient, esthetic and functional results were recorded. RESULTS: The anatomical study showed that sizeable perforators supplying the ALT flap were present in 50 thighs (96.2%), and the perforators supplying the AMT flap were present in 32 thighs (61.5%). The combined ALT and AMT flaps were available in 30 thighs (57.7%).All five combined flaps survived completely. Skin grafts covering the donor sites healed uneventful. The mean follow-up was 9.6 months (range, 6-12 months). No complications were recorded during the follow-up. CONCLUSION: The combined ALT and AMT flap may be used for extensive extremity reconstruction in selected patients for its great maneuverability and acceptable donor-site morbidity.

[Isolation and Identification of Rat Kidney Stem Cells].

OBJECTIVE: To isolate and steadily culture kidney stem cells (KSCs) from rat renal papilla, and to identify the biological characteristics of KSCs. METHODS: KSCs were isolated from the tips of renal papilla in 4 weeks-old Sprague-Dawley rats. The morphology of KSCs was observed under inversion microscope, and the phenotye characteristics of kSCs were identified through flow cytometry and immunofluorescence. The abilities of KSCs in adipogenic and osteogenic differentiation were evaluated. The differences of gene expression between KSCs and rat renal tubular epithelial cells (RTECs)were compared using quantitative real time polymerase chain reaction (qRT-PCR). RESULTS: KSCs showed a spindle-shaped and arborization-like growth pattern. Immunofluorescence indicated that KSCs staining with alpha-sooth muscle actin (α-SMA), Vimentin, N-Cadherin, Nestin, CD133 marker, and without E-cadherin, cytokeratin-18 (CK-18), zona occludens protein-1 (ZO-1). The positive staining of CD29, CD90, CD73 were 99. 0%, 95. 8%, 99. 9% respectively, the positive staining of CD45 was 3. 4%. The positive stainings of stem cell marker CD133 and Nestin were 33. 2% and 70. 2% respectively, while the double staining rate was 31. 4%., KSCs showed positive staining by oil red 0 after adipogenic differentiation, and orange calcium deposition by alizarin red staining after osteogenic differentiation. qRT-PCR showed that the expressions of embryonic stem cell marker Nanog, Oct4/pou5f1,Sox2/sry-box-2 in KSCs were higher than those in RTECs (P< 0.01), and the expressions of mesenchymal marker c-SMA, Vimentin were also higher in KSCs (P<0. 01). Compared with RTECs, the expressions of mature epithelium marker E-Cadherin, CK18 in KSCs were lower (P< 0. 01). CONCLUSION: KSCs were isolated successfully and steadily cultured from the rat renal papilla, which were identified with featured biological characteristics.

Enhancement of tunability of MAPK cascade due to coexistence of processive and distributive phosphorylation mechanisms.

The processive phosphorylation mechanism becomes important when there is macromolecular crowding in the cytoplasm. Integrating the processive phosphorylation mechanism with the traditional distributive one, we propose a mixed dual-site phosphorylation (MDP) mechanism in a single-layer phosphorylation cycle. Further, we build a degree model by applying the MDP mechanism to a three-layer mitogen-activated protein kinase (MAPK) cascade. By bifurcation analysis, our study suggests that the crowded-environment-induced pseudoprocessive mechanism can qualitatively change the response of this biological network. By adjusting the degree of processivity in our model, we find that the MAPK cascade is able to switch between the ultrasensitivity, bistability, and oscillatory dynamical states. Sensitivity analysis shows that the theoretical results remain unchanged within a reasonably chosen variation of parameter perturbation. By scaling the reaction rates and also introducing new connections into the kinetic scheme, we further construct a proportion model of the MAPK cascade to validate our findings. Finally, it is illustrated that the spatial propagation of the activated MAPK signal can be improved (or attenuated) by increasing the degree of processivity of kinase (or phosphatase). Our research implies that the MDP mechanism makes the MAPK cascade become a flexible signal module, and the coexistence of processive and distributive phosphorylation mechanisms enhances the tunability of the MAPK cascade.