A novel prenylated C6–C3 compound with estrogen-like activity from the fruits of Illicium arborescens

A novel C₆–C₃ prenylated compound, illicarborene A (1), together with illioliganfunone D (2), 1-allyl-3,5-dimethoxy-4-(3-methylbut-2-enyloxy)benzene (3), (?)-illicinone A (4), (?)-illicinone B (5) and (?)-illicinone A derivative (6) was isolated and characterized from the fruits of Illicium arborescens Hayata. Compound 1 possesses a new class of tricyclic 6/6/5 ring system. The structure of 1 was determined by spectroscopic analysis such as ¹H–¹H COSY, HMQC, HMBC, and NOESY, and confirmed by chemical reaction to yield 7. Compounds 1–5 were found to increase proliferative activity in primary cell culture of osteoblast cells.     

The DAO Gene Is Associated with Schizophrenia and Interacts with Other Genes in the Taiwan Han Chinese Population

Background

Schizophrenia is a highly heritable disease with a polygenic mode of inheritance. Many studies have contributed to our understanding of the genetic underpinnings of schizophrenia, but little is known about how interactions among genes affect the risk of schizophrenia. This study aimed to assess the associations and interactions among genes that confer vulnerability to schizophrenia and to examine the moderating effect of neuropsychological impairment.

Methods

We analyzed 99 SNPs from 10 candidate genes in 1,512 subject samples. The permutation-based single-locus, multi-locus association tests, and a gene-based multifactorial dimension reduction procedure were used to examine genetic associations and interactions to schizophrenia.

Results

We found that no single SNP was significantly associated with schizophrenia. However, a risk haplotype, namely A-T-C of the SNP triplet rsDAO7-rsDAO8-rsDAO13 of the DAO gene, was strongly associated with schizophrenia. Interaction analyses identified multiple between-gene and within-gene interactions. Between-gene interactions including DAO*DISC1 , DAO*NRG1 and DAO*RASD2 and a within-gene interaction for CACNG2 were found among schizophrenia subjects with severe sustained attention deficits, suggesting a modifying effect of impaired neuropsychological functioning. Other interactions such as the within-gene interaction of DAO and the between-gene interaction of DAO and PTK2B were consistently identified regardless of stratification by neuropsychological dysfunction. Importantly, except for the within-gene interaction of CACNG2, all of the identified risk haplotypes and interactions involved SNPs from DAO.

Conclusions

These results suggest that DAO, which is involved in the N-methyl-d-aspartate receptor regulation, signaling and glutamate metabolism, is the master gene of the genetic associations and interactions underlying schizophrenia. Besides, the interaction between DAO and RASD2 has provided an insight in integrating the glutamate and dopamine hypotheses of schizophrenia.     

Engineering Signal Peptides for Enhanced Protein Secretion from Lactococcus lactis

Lactococcus lactis is an attractive vehicle for biotechnological production of proteins and clinical delivery of therapeutics. In many such applications using this host, it is desirable to maximize secretion of recombinant proteins into the extracellular space, which is typically achieved by using the native signal peptide from a major secreted lactococcal protein, Usp45. In order to further increase protein secretion from L. lactis, inherent limitations of the Usp45 signal peptide (Usp45sp) must be elucidated. Here, we performed extensive mutagenesis on Usp45sp to probe the effects of both the mRNA sequence (silent mutations) and the peptide sequence (amino acid substitutions) on secretion. We screened signal peptides based on their resulting secretion levels of Staphylococcus aureus nuclease and further evaluated them for secretion of Bacillus subtilis α-amylase. Silent mutations alone gave an increase of up to 16% in the secretion of α-amylase through a mechanism consistent with relaxed mRNA folding around the ribosome binding site and enhanced translation. Targeted amino acid mutagenesis in Usp45sp, combined with additional silent mutations from the best clone in the initial screen, yielded an increase of up to 51% in maximum secretion of α-amylase while maintaining secretion at lower induction levels. The best sequence from our screen preserves the tripartite structure of the native signal peptide but increases the positive charge of the n-region. Our study presents the first example of an engineered L. lactis signal peptide with a higher secretion yield than Usp45sp and, more generally, provides strategies for further enhancing protein secretion in bacterial hosts.     

The Years of the Monkey

The fact that mammals are diploid sets a barrier to rapidly understand the function of non-coding and coding genes in the genome. Recently, Yang et al. reported successful derivation of monkey haploid embryonic stem cells from parthenotes, which provide an effective platform for studying mammalian gene function and enable reverse genetic screening of genes for recessive phenotypes in monkeys.According to the Zodiac in the Chinese Calendar, the next year of the monkey is not slated until February 2016, but a recent paper in this month''s Cell Research suggests that it may have arrived early for the field of stem cell biology. In a stunning technical “Tour de Force”, Jinsong Li and his colleagues report for the first time the generation of several independent haploid monkey embryonic stem (ES) cell lines¹, building on the previous work from their lab and others that described the generation of murine haploid ES cell lines^2,3,4,5 (Figure 1). They first activated metaphase II monkey oocytes with ionomycin followed by cycloheximide treatment. These activated oocytes could develop into blastocysts in vitro and haploid ES cells (haESCs) can be derived by culturing the inner cell mass in a standard monkey ES cell culture system and using Hoechst FACS technique. Remarkably, one of the cell lines remained stable during long term passage, obviating the need for FACS sorting for the haploid cell lines during subsequent propagation. The cell lines can be genetically manipulated by insertional mutagenesis or by PiggyBac transposon technology, suggesting the possibility of genome-wide screening strategies. In this regard, a series of parallel scientific advances suggest that this technology platform may be particularly timely as the field of stem cell biology moves towards regenerative medicine and therapeutics.Open in a separate windowFigure 1The scheme of parthenogenetic (PG) and androgenetic (AG) haploid embryonic stem cells (haESCs) derivation. (A) For the generation of PG-haESCs, metaphase II oocytes were activated with either strontium chloride (SrCl₂) for mice or ionomycin/cycloheximide (CHX) for monkeys and further cultivated to the blastocyst stage. With the help of Hoechst FACS technique, PG-haESCs can be derived. (B) For the generation of AG-haESCs, metaphase II oocytes were enucleated followed by sperm injection. In addition, the reconstructed oocytes were activated with SrCl₂ for mice and further developed to the blastocyst stage in vitro. AG-haESCs can be derived by several rounds of Hoechst FACS based on DNA contents. The derivation of non-human primate AG-haESCs has not been reported yet.For many years, it has proven quite difficult to engineer site-specific mutations, knock-ins, and knock-outs in human ES or induced pluripotent stem (iPS) cells, and only a handful of genetically engineered lines have been created by conventional homologous recombination strategies⁶. However, recent advances in RNA-guided nuclease technology has led to a marked improvement in the efficiency of the knockout of genes in human pluripotent stem cells⁷, suggesting that it may be possible to create knock-out haploid non-human primate (NHP) ES cell lines that harbor specific disease genes and surrogate reporter readouts, and then to look for genetic complementation that could identify critical genes that could be potential drug targets. A library of individual NHP haploid ES cell lines that harbor a loss-of-function mutation across the entire NHP genome could find multiple uses in quickly identifying signaling pathways in differentiated cell types. Given recent advances in screening in human ES and iPS cell lines⁸, direct drug screening on the haploid monkey ES cell lines should also be possible. In addition, it will likely be possible to set up genome-wide screening to systematically identify entire network of genes that drive specific differentiation events, and early steps of primate organogenesis. If androgenetic NHP haploid cell lines can be developed (see Figure 1), a leap in the efficiency of the generation of monkey KO animal models could be envisioned over the long term. In this regard, the recent generation of chimeric monkeys⁹, as well as future technical advances related to this achievement, could become of significant interest.At the same time, the study indirectly raises the query as to the need for monkey model systems when the technology for genetic manipulation in the mouse is without peer, and human ES and iPS cell lines can now be easily generated and genetically manipulated. The recent pronouncement of the termination of NIH support for primate research (http://news.sciencemag.org/people-events/2013/06/nih-will-retire-most-research-chimps-end-many-projects), along with the growing awareness of the need to re-examine the need for NHP models, suggests that there must be very solid scientific grounds for pursuing NHP model systems in the future.In this regard, a growing body of evidence is now pointing to the lack of fidelity of mouse models of human disease to the in vivo human setting, a problem that has plagued cancer therapeutics for decades. Recently, the lack of predictability of human responses from models of murine sepsis has been cogently made¹⁰, and the divergence in the physiology of mice and humans, particularly in terms of metabolism and cardiovascular, are enormous. The complexity and scalability of primate versus murine organogenesis also may be an issue. For example, the human heart is 10 000 times larger than the murine, has a much larger diversity of cell types, and a level of tertiary morphology that is not found in the murine heart (for review see¹¹). Murine cardiogenesis is largely completed with 48 h, while human cardiogenesis occurs over months, and recent studies that suggest a much larger diversity and markedly extended period of proliferation of the family of heart progenitors in the human fetal versus murine heart¹². To date, there are no approved drugs that have come from genetically engineered murine models of cardiovascular (CV) disease, and the biggest CV drugs have actually been discovered based on human genetics (statins, PCSK9, etc.). The increased importance of CV side effects for new drugs in the diabetes space, as well as for other chronic diseases, points to the importance of their study in more sophisticated primate systems, as all these drugs (Avandia, Vioxx, etc.) had cleared conventional screening in rodent model systems. Given the above, we may have to put the Chinese Calendar on auto-repeat mode, as we enter the “Years of the Monkey” in this decade and the next.     

<Emphasis Type="Italic">Sorting nexin 24</Emphasis> genetic variation associates with coronary artery aneurysm severity in Kawasaki disease patients

Background

The sorting nexin (SNX) family is involved in endocytosis and protein trafficking and plays multiple roles in various diseases. The role of SNX proteins in Kawasaki disease (KD) is not known. We attempted to test whether genetic SNX variation associates with the risk of coronary artery aneurysm (CAA) formation in KD.

Methods and results

Chi-square tests were used to identify SNX24 genetic variants associated with KD susceptibility and CAA formation in KD; models were adjusted for fever duration and time of first administration of intravenous immunoglobulin. We obtained clinical characteristics and genotypes from KD patients (76 with CAA and 186 without CAA) in a population-based retrospective KD cohort study (n?=?262). Clinical and genetic factors were associated with CAA formation in KD. In addition, endothelial cell inflammation was evaluated. Significant correlation was observed between KD with CAA complications and the rs28891 single-nucleotide polymorphism in SNX24. Patients with CC?+?CT genotypes had lesser CAA complications. In lipopolysaccharide-treated human umbilical vein endothelial cells, siRNA knockdown of SNX24 significantly decreased gene expression of the proinflammatory cytokines IL-1 beta, IL-6, and IL-8.

Conclusions

Polymorphisms in SNX24 may be used as genetic markers for the diagnosis and prognosis of CAA formation in KD.

     

Age-Dependent Changes in Geometry,Tissue Composition and Mechanical Properties of Fetal to Adult Cryopreserved Human Heart Valves

There is limited information about age-specific structural and functional properties of human heart valves, while this information is key to the development and evaluation of living valve replacements for pediatric and adolescent patients. Here, we present an extended data set of structure-function properties of cryopreserved human pulmonary and aortic heart valves, providing age-specific information for living valve replacements. Tissue composition, morphology, mechanical properties, and maturation of leaflets from 16 pairs of structurally unaffected aortic and pulmonary valves of human donors (fetal-53 years) were analyzed. Interestingly, no major differences were observed between the aortic and pulmonary valves. Valve annulus and leaflet dimensions increase throughout life. The typical three-layered leaflet structure is present before birth, but becomes more distinct with age. After birth, cell numbers decrease rapidly, while remaining cells obtain a quiescent phenotype and reside in the ventricularis and spongiosa. With age and maturation–but more pronounced in aortic valves–the matrix shows an increasing amount of collagen and collagen cross-links and a reduction in glycosaminoglycans. These matrix changes correlate with increasing leaflet stiffness with age. Our data provide a new and comprehensive overview of the changes of structure-function properties of fetal to adult human semilunar heart valves that can be used to evaluate and optimize future therapies, such as tissue engineering of heart valves. Changing hemodynamic conditions with age can explain initial changes in matrix composition and consequent mechanical properties, but cannot explain the ongoing changes in valve dimensions and matrix composition at older age.     

Do the Preferences of Healthcare Provider Selection Vary among Rural and Urban Patients with Different Income and Cause Different Outcome?

BackgroundEqual access to healthcare facilities and high-level quality of care are important strategies to eliminate the disparity in outcome of care. However, the existing literature regarding how urban or rural dwelling patients with different income level select healthcare providers is insufficient. The purposes of this study were to examine whether differences of healthcare provider selection exist among urban and rural coronary artery bypass surgery (CABG) patients with different income level. If so, we further investigated the associated impact on mortality.MethodsA retrospective, multilevel study design was conducted using claims data from 2007–2011 Taiwan’s Universal Health Insurance Scheme. Healthcare providers’ performance and patients’ travelling distance to hospitals were used to define the patterns of healthcare provider selection. Baron and Kenny’s procedures for mediation effect were conducted.ResultsThere were 10,108 CABG surgeries included in this study. The results showed that urban dwelling and higher income patients were prone to receive care from better-performance providers. The travelling distances of urban dwelling patients was 15 KM shorter, especially when they received better-performance provider’s care. The results also showed that the difference of healthcare provider selection and mortality rate existed between rural and urban dwelling patients with different income levels. After the procedure of mediation effect testing, the results showed that the healthcare provider selection partially mediated the relationships between patients’ residential areas with different income levels and 30-day mortality.ConclusionPreferences of healthcare provider selection vary among rural and urban patients with different income, and such differences partially mediated the outcome of care. Health authorities should pay attention to this issue, and propose appropriate solutions to eliminate the disparity in outcome of CABG care.     

Fine control of endothelial VEGFR-2 activation: caveolae as fluid shear stress shelters for membrane receptors

Biomechanics and Modeling in Mechanobiology - Recent experimental evidence points to the possibility that cell surface-associated caveolae may participate in mechanotransduction. The particular...     

Population and Single-Cell Analysis of Human Cardiogenesis Reveals Unique LGR5 Ventricular Progenitors in Embryonic Outflow Tract

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Warmest Congratulations to Dr. Yuan-Cheng Fung at His Centennial Celebration

Professor Y.C. Fung has made tremendous impacts on science, engineering and humanity through his research and its applications, by setting the highest standards, through educating many students and their students, and providing his exemplary leadership. He has applied his profound knowledge and elegant analytical methods to the study of biomedical problems with rigor and excellence. He established the foundations of biomechanics in living tissues and organs. Through his vision of the power of “making models” to explain and predict biological phenomena, Dr. Fung opened up new vista for bioengineering, from organs-systems to molecules-genes, and has provided the foundation of research activities in many institutions in the United States and the world. He has made outstanding contributions to education in bioengineering, service to professional organizations, and translation to industry and clinical medicine. He is widely recognized as the Father of Biomechanics and the leading Bioengineer in the world. His extraordinary achievements and commands in science, engineering and the arts make him a Renaissance Man for the world.