Exploring AKIP1 function in the heart

Heart failure (HF) is the common end stage syndrome of many cardiac disorders, including valve insufficiency (volume overload), hypertension (pressure overload), myocardial infarction and cardiomyopathies. These different initial events all result in altered ventricular wall stress triggering cardiac remodeling. One of the main processes that contributes to cardiac remodeling is cardiomyocyte growth (hypertrophy). Induction of hypertrophy is accompanied by marked changes in gene expression profiles of which the re-expression of fetal genes, the so called “fetal gene program” is well known1,2. The aim of this thesis was to generate an inventory of gene expression changes specific for cardiomyocyte hypertrophy and to further investigate the role of these changes in hypertrophy development (chapter 1). In particular, we explored the function of A kinase interacting protein 1 (AKIP1), which was identified in the inventory as a novel hypertrophy associated gene. That cardiomyocyte growth and changes in cardiomyocyte function are the underlying causes of cardiac hypertrophy and HF development has been recognized for ages. Unravelling the molecular mechanism underlying these processes has, however, only started in the last decades and it has become clear that these changes are very complex. In chapter 2, we reviewed the current knowledge on gene expression regulation during hypertrophy development. We described how neurohormonal and biomechanical signals are transduced to the nucleus and affect a set of transcription factors and chromatin modulators. Calcium signaling and protein (de)phosphorylation plays an essential role in this transduction process. Multiple transcription factors, including MEF2, GATA, Nkx-2.5 and NFAT, cooperate in controlling cardiomyocyte gene expression and binding sites for these proteins have been found in promoters of many hypertrophy associated genes. However, even for an extensively explored gene like ANP (atrial natriuretic protein) the regulation of its expression in vivo is still mysterious3. Genetic modulation of signal transduction pathways and transcription factors in in vitro studies and in animal models has shown that targeting these systems allows modulation of hypertrophy development. However, due to their central role, not only in cardiomyocytes, but also in many other cells it is unlikely that targeting these central systems will provide therapeutic opportunities. We therefore postulated that it might be more promising to investigate the potential downstream targets of these pathways. Several studies that target downstream genes are currently underway and provide promising results, like BNP4, SERCA5, and myosin6. Generating an inventory of hypertrophy associated genes may therefore allow the identification of new potential targets against HF

Multiple shoot induction and rooting of Paeonia lactiflora ‘Da Fu Gui’

Underground buds of herbaceous peony (Paeonia lactiflora Pall.) ‘Da Fu Gui’ were micropropagated in vitro. The basic processes including culture initiation, shoot induction, axillary shoot proliferation and rooting were established. The best initial medium of ‘Da Fu Gui’ was half-strength MS (Murashige and Skoog) medium (double-strength Ca2+) supplemented with 0.5 mg l-1 6-benzylaminopurine (BA) plus 0.5 mg l-1 gibberellic acid (GA3). The best medium for axillary shoot induction was half-strength MS medium (double-strength Ca2+) supplemented with 1.0 mg l-1 BA plus 0.5 mg l-1 kinetin (Kin), while 0.5 mg l-1 BA + 0.3 mg l-1 Kin was best for shoot proliferation. Shoot height at the time of inoculation had a great effect on proliferation and growth of ‘Da Fu Gui’. Putrescine (Put) (0.5 to 5.0 mg l-1) prevented rooting of ‘Da Fu Gui’ but it favored the development of roots. Highest rooting percentage was observed on half-strength MS medium (double-strength Ca2+) supplemented with 1 mg l-1 indole-3-butyric acid (IBA).Key words: Herbaceous peony, underground buds, axillary shoots, micropropagation

Modified Projective Synchronization between Different Fractional-Order Systems Based on Open-Plus-Closed-Loop Control and Its Application in Image Encryption

A new general and systematic coupling scheme is developed to achieve the modified projective synchronization (MPS) of different fractional-order systems under parameter mismatch via the Open-Plus-Closed-Loop (OPCL) control. Based on the stability theorem of linear fractional-order systems, some sufficient conditions for MPS are proposed. Two groups of numerical simulations on the incommensurate fraction-order system and commensurate fraction-order system are presented to justify the theoretical analysis. Due to the unpredictability of the scale factors and the use of fractional-order systems, the chaotic data from the MPS is selected to encrypt a plain image to obtain higher security. Simulation results show that our method is efficient with a large key space, high sensitivity to encryption keys, resistance to attack of differential attacks, and statistical analysis

Characterization and identification of the integrin family in silkworm, Bombyx mori

YesAs an important economic insect, Bombyx mori is also a useful model organism for lepidopteran insect. Integrins are evolutionarily conserved fromsponges to humans, and play vital roles inmany physiological and pathological processes. To explore their diverse functions of integrins in insect, eleven integrins including sixα and five β subunitswere cloned and characterized fromsilkworm. Our results showed that integrins fromsilkwormown more family members compared to other invertebrates. Among those α subunits, integrins α1, α2, and the other four subunits belong to PS1, PS2, and PS3 groups, respectively. The β subunits mainly gather in the insect βν group except the β1 subunit which belongs to the insect β group. Expression profiles demonstrated that the integrins exhibited distinct patterns, but were mainly expressed in hemocytes. α1 and β2 subunits are the predominant ones either in the embryogenesis or larva stages. Interestingly, integrins were significantly up-regulated after stimulated by 20-hydroxyecdysone (20-E) in vivo. These results indicate that integrins performdiverse functions in hemocytes of silkworm. Overall, our results provide a newinsight into the functional and evolutionary features of integrins.National Basic Research Programof China (No. 2012cb114603), the Research Fund for the Doctoral Program of Higher Education of China (20130182110003), the Natural Science Foundation of Chongqing (cstc2013jcyjys0007), and the Fundamental Research Funds for the Central Universities (SWU111014)

Multi-Stage Tuberculosis Subunit Vaccine Candidate LT69 Provides High Protection against Mycobacterium tuberculosis Infection in Mice

Effective tuberculosis (TB) vaccine should target tubercle bacilli with various metabolic states and confer long-term protective immunity. In this study, we constructed a novel multi-stage TB subunit vaccine based on fusion protein ESAT6-Ag85B-MPT64(190-198)-Mtb8.4-HspX (LT69 for short) which combined early expressed antigens and latency-associated antigen. The fusion protein was mixed with an adjuvant being composed of N, N’-dimethyl-N, N’-dioctadecylammonium bromide (DDA) and polyriboinosinic polyribocytidylic acid (PolyI:C) to construct subunit vaccine, whose immunogenicity and protective ability were evaluated in C57BL/6 mice. The results showed that LT69 had strong immunogenicity and high protective effect against Mycobacterium tuberculosis (M. tuberculosis) H37Rv aerosol challenge. Low-dose (2 μg) of LT69 generated long-term immune memory responses and provided effective protection, which was even higher than traditional vaccine BCG did at 30 weeks post the last vaccination. In conclusion, multistage subunit vaccine LT69 showed high and long-term protection against M. tuberculosis infection in mice, whose effect could be enhanced by using a relative low dosage of antigen.National Major Science and Technology Projects (China) (2012ZX10003-008-006)National Natural Science Foundation (China) (31470895)National Natural Science Foundation (China) (81072499)China. Ministry of Education (Doctoral Fund 20120211110038

Gestational Exposure to Particulate Matter 2.5 (PM2.5) Leads to Spatial Memory Dysfunction and Neurodevelopmental Impairment in Hippocampus of Mice Offspring

Prenatal exposure to air pollutants has long-term impact on growth retardation of nervous system development and is related to central nervous system diseases in children. However, it is not well-characterized whether gestational exposure to air pollutants affects the development of nervous system in offspring. Here, we investigated the effects of gestational exposure to particulate matter 2.5 (PM2.5) on hippocampus development in mice offspring, through neurobehavioral, ultrastructural, biochemical and molecular investigations. We found that spatial memory in mice offspring from PM2.5 high-dosage group was impaired. Next, hippocampal ultrastructure of the mice offspring in puberty exhibited mitochondrial damage related to PM2.5 exposure. Interestingly, EdU-positive cells in the subgranular zone (SGZ) of offspring from PM2.5 high-dosage group decreased, with NeuN+/EdU+cells reduced significantly. Furthermore, the numbers of NeuN+/TUNEL+, GFAP+/TUNEL+, and Iba1+/TUNEL+ double-labeled cells increased with PM2.5 exposure in a dosage-dependent manner. In addition, gestational exposure to PM2.5 resulted in increased levels of both mRNAs and proteins involved in apoptosis, including caspase-3, -8, -9, p53, and c-Fos, and decreased Bcl-2/Bax ratios in the hippocampus of mice offspring. Moreover, gestational exposure to PM2.5 was dosage-dependently associated with the increased secretions of inflammatory proteins, including NF-κB, TNF-α, and IL-1β. Collectively, our results suggest that gestational exposure to PM2.5 leads to spatial memory dysfunction and neurodevelopmental impairment by exerting effects on apoptotic and neuroinflammatory events, as well as the neurogenesis in hippocampus of mice offspring

Cardiac Function and Architecture Are Maintained in a Model of Cardiorestricted Overexpression of the Prorenin-Renin Receptor

The (pro)renin-renin receptor, (P)RR has been claimed to be a novel element of the renin-angiotensin system (RAS). The function of (P)RR has been widely studied in renal and vascular pathology but the cardio-specific function of (P)RR has not been studied in detail. We therefore generated a transgenic mouse (Tg) with cardio-restricted (P)RR overexpression driven by the alpha-MHC promotor. The mRNA expression of (P)RR was ∼170-fold higher (P<0.001) and protein expression ∼5-fold higher (P<0.001) in hearts of Tg mice as compared to non-transgenic (wild type, Wt) littermates. This level of overexpression was not associated with spontaneous cardiac morphological or functional abnormalities in Tg mice. To assess whether (P)RR could play a role in cardiac hypertrophy, we infused ISO for 28 days, but this caused an equal degree of cardiac hypertrophy and fibrosis in Wt and Tg mice. In addition, ischemia-reperfusion injury was performed in Langendorff perfused isolated mouse hearts. We did not observe differences in parameters of cardiac function or damage between Wt and Tg mouse hearts under these conditions. Finally, we explored whether the hypoxia sensing response would be modulated by (P)RR using HeLa cells with and without (P)RR overexpression. We did not establish any effect of (P)RR on expression of genes associated with the hypoxic response. These results demonstrate that cardio-specific overexpression of (P)RR does not provoke phenotypical differences in the heart, and does not affect the hearts’ response to stress and injury. It is concluded that increased myocardial (P)RR expression is unlikely to have a major role in pathological cardiac remodeling