Chronic heart failure (CHF) is characterized by increased sympathetic tone. The glutamatergic input in the rostral ventrolateral medulla (RVLM), which is a key region involved in sympathetic outflow, seems not to be involved in the generation of sympathetic tone in the normal state. The aim of this study was to determine the role of the RVLM glutamate receptors in generation of sympathetic tone in CHF. CHF was produced by left coronary artery ligation. Bilateral microinjection of the glutamate receptor antagonist kynurenic acid (KYN), the N-methyl-D-aspartate (NMDA) receptor antagonist D-AP5, or the non-NMDA receptor antagonist CNQX into the RVLM dose-dependently reduced resting blood pressure and renal sympathetic nerve activity in CHF but not in sham rats. Picoinjection of KYN (100 pmol in 5 nl) significantly decreased the basal discharge by 47% in 25 RVLM presympathetic neurons in CHF rats, In contrast, KYN had no effect on the discharge in all 22 RVLM presympathetic neurons tested in sham rats. These data suggest that upregulated glutamate receptors, including NMDA and non-NMDA, in the RVLM are involved in tonic control of elevated sympathetic tone in CHF.
sympathoexcitation; glutamate receptors; micro/picoinjection; extracellular recording; presympathetic neuron
To evaluate the relationship between different hCG priming-to-oocyte retrieval intervals and assisted reproductive technology (ART) outcome.
We systematically searched PubMed, EMBASE, the Cochrane Library, Science Citation Index, Chinese biomedicine (CBM) literature database, and Chinese Journal Full-text Database for randomized controlled trials (RCTs) published up to November 2010. Data was extracted from the studies by two independent reviewers. Statistical analysis was performed with Cochrane Collaboration’s Review Manager (RevMan) 5.0.2. From extracted data, Risk Ratio (RR) with 95% confidence interval (CI) was calculated.
5 RCTs totaling 895 participants were included. Oocyte maturation rate was higher in the long interval group compared with short interval group (RR, 0.67; 95% CI, 0.62–0.73). There were no significant difference between the two groups with regard to fertilization rate (RR, 0.99; 95% CI, 0.94–1.04), implantation rate (RR, 0.91; 95% CI, 0.40–2.04), and pregnancy rate (RR, 0.79; 95% CI, 0.58–1.08).
The percentage of mature (MII) oocytes can be increased by prolonging the interval between hCG priming and oocyte retrieval. The prolonged interval could not increase the fertilization rate, implantation rate, and pregnancy rate. Although there was evidence to confirm the results, they still need to be confirmed by large-sample, multicenter, randomized controlled trials. The time interval dependent mechanisms responsible for ART performance need to be elucidated.
Human chorionic gonadotropin; Oocyte retrieval; Time interval; Infertility; Assisted reproductive technology; Meta-analysis
Up-regulation of Angiotensin type 1 receptors (AT1R) in the rostral ventrolateral medulla (RVLM) contributes to the sympatho-excitation in the chronic heart failure (CHF). However, the role of AT2R is not clear. In this study, we measured AT1R and AT2R protein expression in the RVLM and determined their effects on renal sympathetic nerve activity (RSNA), blood pressure (BP), and heart rate (HR) in anaesthetized sham and CHF rats. We found that: (1) while AT1R expression in the RVLM was up-regulated, the AT2R was significantly down-regulated (CHF: 0.06 ± 0.02 vs sham: 0.15 ± 0.02, P < 0.05); (2) simultaneously stimulating RVLM AT1R and AT2R by Ang II evoked sympatho-excitation, hypertension, and tachycardia in both sham and CHF rats, with greater responses in CHF; (3) stimulating RVLM AT1R with Ang II plus the specific AT2R antagonist PD123319 induced a larger sympatho-excitatory response than simultaneously stimulating AT1R and AT2R in sham rats, but not in CHF; (4) activating RVLM AT2R with CGP42112 induced a sympatho-inhibition, hypotension, and bradycardia only in sham rats (RSNA: 36.4 ± 5.1 % of baseline vs 102 ± 3.9 % of baseline in aCSF, P < 0.05); (5) pretreatment with ETYA, a general inhibitor of AA metabolism, into the RVLM attenuates the CGP42112 induced sympatho-inhibition. These results suggest that AT2R in the RVLM exhibits an inhibitory effect on sympathetic outflow, which is, at least partially, mediated by an AA metabolic pathway. These data implicate a down regulation in the AT2R as a contributory factor in the sympatho-excitation in CHF.
Angiotensin II type 2 receptor; Angiotensin II type 1 receptor; rostral ventrolateral medulla; sympathetic outflow
In the crystal structure of the title compound, C14H14F3O7P, the central chain, which connects the phosphate bicyclic system and the benzene ring, is made up of an approximately planar C—C(O)—O—C(H2) fragment and a C(H2)—O—C(Ph) link; the mean planes make a dihedral angle of 75.9 (2)°. The F atoms are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4.
Activation of the cardiac “sympathetic afferent” reflex (CSAR) has been reported to depress the arterial baroreflex and enhance the arterial chemoreflex via a central mechanism. In the present study, we used single-unit extracellular recording techniques to examine the effects of stimulation of cardiac sympathetic afferents on baro- or chemosensitive neurons in the nucleus tractus solitarius (NTS) in anesthetized rats. Of 54 barosensitive NTS neurons tested for their response to epicardial application of capsaicin (0.4 μg), 38 were significantly (P<0.01) inhibited by 38 % while 16 did not respond. Of 42 NTS chemosensitive neurons tested for their response to capsaicin, 33 were significantly (P<0.01) excited by 47 % while 9 did not respond. In addition, of 12 both barosensitive and chemosensitive NTS neurons tested for capsaicin, 2 were excited, 7 were inhibited, and 3 did not respond. In conclusion, this study indicates that CSAR activation inhibited NTS barosensitive neurons and excited NTS chemosensitive neurons, suggesting that the NTS plays an important role in processing the interactions between these cardiovascular reflexes.
cardiovascular reflexes; sympathetic activity; capsaicin; extracellular recording; baro-/chemosensitive neuron
Angiotensin II (Ang II)–induced arterial baroreflex dysfunction is associated with superoxide generation in the brain. Exercise training (EX) improves baroreflex function and decreases oxidative stress in cardiovascular diseases linked to elevated central Ang II. The aim of this study was to determine whether previous EX prevents baroreflex impairment caused by central administration of exogenous Ang II via an Ang II–superoxide mechanism. Four groups of rats were used: non-EX artificial cerebrospinal fluid infused, non-EX Ang II infused, EX artificial cerebrospinal fluid infused, and EX Ang II infused. Rats were treadmill trained for 3 to 4 weeks and subjected to intracerebroventricular infusion of Ang II over the last 3 days of EX. Twenty-four hours after the end of EX, the arterial baroreflex was assessed in anesthetized rats. Compared with non-EX artificial cerebrospinal fluid–infused rats, Ang II significantly decreased baroreflex sensitivity (maximum gain: 3.0 ± 0.2% of maximum per millimeter of mercury versus 1.6 ± 0.1% of maximum per millimeter of mercury; P < 0.01), which was abolished by acute intracerebroventricular infusion of the Ang II type 1 receptor antagonist losartan and the reduced nicotinamide-adenine dinucleotide phosphate oxidase inhibitor apocynin. EX prevented the decrease in baroreflex sensitivity and downregulated Ang II type 1 receptor and NADPH oxidase subunit protein expression in the paraventricular nucleus of Ang II–infused rats. Finally, EX decreased superoxide production in the paraventricular nucleus of Ang II–infused rats. These results indicate that EX improves arterial baroreflex function in conditions of high brain Ang II, which is mediated by the central Ang II type 1 receptor and associated with a reduction in central oxidative stress.
exercise; baroreflex; sympathetic nerve activity; reactive oxygen species; AT1 receptor
Abnormal behavior of the cardiac ryanodine receptor (RyR2) has been linked to cardiac arrhythmias and heart failure (HF) after Myocardial infarction (MI). It has been proposed that protein kinase A (PKA) hyperphosphorylation of the RyR2 at a single residue, Ser-2808 is a critical mediator of RyR dysfunction, depressed cardiac performance and HF after MI.
We used a mouse model (RyRS2808A) in which PKA hyperphosphorylation of the RyR2 at Ser-2808 is prevented to determine whether loss of PKA phosphorylation at this site averts post MI cardiac pump dysfunction.
Methods and Results
MI was induced in WT and S2808A mice. Myocyte and cardiac function were compared in WT and S2808A animals before and after MI. The effects of the PKA activator Isoproterenol (Iso) on L-type Ca2+ current (ICaL), contractions and [Ca2+]I transients were also measured. Both WT and S2808A mice had depressed pump function after MI and were no differences between groups. MI size was also identical in both groups. L type Ca2+ current, contractions, Ca2+ transients and SR Ca2+ load were also not significantly different in WT versus S2808A myocytes either before or after MI. Iso effects on Ca2+ current, contraction, Ca2+ transients and SR Ca2+ load were identical in WT and S2808A myocytes before and after MI at both low and high concentrations.
These results strongly support the idea that PKA phosphorylation of RyR-S2808 is irrelevant to the development of cardiac dysfunction after MI, at least in the mice used in this study.
Myocardial infarction; ryanodine receptor; heart failure; PKA hyperphosphorylation
Computational modeling of cardiac electrophysiology is a powerful tool for studying arrhythmia mechanisms. In particular, cardiac models are useful for gaining insights into experimental studies, and in the foreseeable future they will be used by clinicians to improve therapy for the patients suffering from complex arrhythmias. Such models are highly intricate, both in their geometric structure and in the equations that represent myocyte electrophysiology. For these models to be useful in a clinical setting, cost-effective solutions for solving the models in real time must be developed. In this work, we hypothesized that low-cost GPGPU-based hardware systems can be used to accelerate arrhythmia simulations. We ported a two dimensional monodomain cardiac model and executed it on various GPGPU platforms. Electrical activity was simulated during point stimulation and rotor activity. Our GPGPU implementations provided significant speedups over the CPU implementation: 18X for point stimulation and 12X for rotor activity. We found that the number of threads that could be launched concurrently was a critical factor in optimizing the GPGPU implementations.
The formation of compulsive pattern of drug use is related to abnormal regional neural activity and functional reorganization in the heroin addicts’ brain, but the relationship between heroin-use-induced disrupted local neural activity and its functional organization pattern in resting-state is unknown.
With fMRI data acquired during resting state from 17 male heroin dependent individuals (HD) and 15 matched normal controls (NC), we analyzed the changes of amplitude of low frequency fluctuation (ALFF) in brain areas, and its relationship with history of heroin use. Then we investigated the addiction related alteration in functional connectivity of the brain regions with changed ALFF using seed-based correlation analysis. Compared with NC, the ALFF of HD was obviously decreased in the right caudate, right dorsal anterior cingulate cortex (dACC), right superior medial frontal cortex and increased in the bilateral cerebellum, left superior temporal gyrus and left superior occipital gyrus. Of the six regions, only the ALFF value of right caudate had a negative correlation with heroin use. Setting the six regions as “seeds”, we found the functional connectivity between the right caudate and dorsolateral prefrontal cortex (dlPFC) was reduced but that between the right caudate and cerebellum was enhanced. Besides, an abnormal lateral PFC-dACC connection was also observed in HD.
The observations of dysfunction of fronto-striatal and fronto-cerebellar circuit in HD implicate an altered balance between local neuronal assemblies activity and their integrated network organization pattern which may be involved in the process from voluntary to habitual and compulsive drug use.
Granule neurons have a central role in cerebellar function via their synaptic interactions with other neuronal cell types both within and outside this structure. Establishment of these synaptic connections and its control is therefore essential to their function. Both intrinsic as well as environmental mechanisms are required for neuronal development and formation of neuronal circuits, and a key but poorly understood question is how these various events are coordinated and integrated in maturing neurons. In this review, we summarize recent work on the role of the Nuclear Factor I family in the transcriptional programming of cerebellar granule neuron maturation and synapse formation. In particular, we describe (1) the involvement of this family of factors in key developmental steps occurring throughout postmitotic granule neuron development, including dendrite and synapse formation and synaptic receptor expression, and (2) the mediation of these actions by critical downstream gene targets that control cell–cell interactions. These findings illustrate how Nuclear Factor I proteins and their regulons function as a “bridge” between cell-intrinsic and cell-extrinsic interactions to control multiple phases of granule neuron development.
Neuronal differentiation; Transcription factor; Axonogenesis; Migration; Dendritogenesis; Synaptogenesis
The nicotinic acetylcholine receptor (nAChR) is an important therapeutic target for a wide range of pathophysiological conditions, for which rational drug designs often require receptor structures at atomic resolution. Recent proof-of-concept studies demonstrated a water-solubilization approach to structure determination of membrane proteins by NMR (Slovic et al., PNAS, 101: 1828-1833, 2004; Ma et al., PNAS, 105: 16537-42, 2008). We report here the computational design and experimental characterization of WSA, a water-soluble protein with ∼83% sequence identity to the transmembrane (TM) domain of the nAChR α1 subunit. Although the design was based on a low-resolution structural template, the resulting high-resolution NMR structure agrees remarkably well with the recent crystal structure of the TM domains of the bacterial Gloeobacter violaceus pentameric ligand-gated ion channel (GLIC), demonstrating the robustness and general applicability of the approach. NMR T2 dispersion measurements showed that the TM2 domain of the designed protein was dynamic, undergoing conformational exchange on the NMR timescale. Photoaffinity labeling with isoflurane and propofol photolabels identified a common binding site in the immediate proximity of the anesthetic binding site found in the crystal structure of the anesthetic-GLIC complex. Our results illustrate the usefulness of high-resolution NMR analyses of water-solubilized channel proteins for the discovery of potential drug binding sites.
The Hyp mouse is a commonly used model for the study of the phosphate wasting disease X-linked hypophosphataemia. The defect in this mouse line is a deletion that includes exons 16 to 22 of Phex, although the exact extent of this X chromosome deletion remains unknown. This complicates genotyping which increases costs, time and difficulty of working with this important model. We aimed to determine the molecular breakpoints of this deletion in order develop a robust assay for its detection. We designed short mapping PCRs around the Phex locus to refine the putative breakpoint locations, then used gap PCR to amplify a product containing the breakpoint junction. DNA sequencing showed the deleted region was approximately 297 kb, significantly larger than previous reports, but did not contain any genes other than Phex. DNA sequence analysis revealed that this deletion may be the result of microhomology-mediated end joining. Finally, we designed a multiplex PCR assay for genotyping Hyp colonies and validated it using a panel of Hyp colony mice. This study provides confirmation of the Hyp phenotype as a single gene defect, a potential mechanism for its formation and an improved method for genotyping that will make working with this strain significantly easier.
X-linked hypophosphataemia; Hyp mouse; deletion
Many in vitro studies of the analysis of the lactoferrin (LF) effect on cells have been reported. However, no study has yet investigated the effect of LF on osteogenic differentiation of human adipose-derived stem cells (hADSCs). The aim of this study was to evaluate the effect of LF on osteogenic differentiation of human adipose stem cells.
The hADSCs were cultured in an osteogenic medium with 0, 10, 50 and 100 μg/ml LF, respectively. hADSC proliferation was analysed by Cell Counting Kit-8 (CCK-8) assay, and cell osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity assay, von Kossa staining and real-time polymerase chain reaction (RT-PCR).
Cell proliferation was significantly increased by LF in a dose-dependent manner from days 4 to 14. Cells cultured with 100 μg/ml LF presented a higher activity compared with the control. The deposition of calcium was increased after the addition of LF. The mRNA expression of type I collagen (COL-I), ALP, osteocalcin (OCN) and RUNX2 increased markedly as a result of LF treatment.
We have shown for the first time that LF could promote the proliferation and osteogenic differentiation of hADSCs, which could be a promising approach for enhancing osteogenic capacity of cell-based construction in bone tissue engineering.
The 2009 flu pandemic involved the emergence of a new strain of a swine-origin H1N1 influenza virus (S-OIV H1N1) that infected almost every country in the world. Most infections resulted in respiratory illness and some severe cases resulted in acute lung injury. In this report, we are the first to describe a mouse model of S-OIV virus infection with acute lung injury and immune responses that reflect human clinical disease. The clinical efficacy of the antiviral oseltamivir (Tamiflu) administered in the early stages of S-OIV H1N1 infection was confirmed in the mouse model. Moreover, elevated levels of IL-17, Th-17 mediators and IL-17-responsive cytokines were found in serum samples of S-OIV-infected patients in Beijing. IL-17 deficiency or treatment with monoclonal antibodies against IL-17-ameliorated acute lung injury induced by the S-OIV H1N1 virus in mice. These results suggest that IL-17 plays an important role in S-OIV-induced acute lung injury and that monoclonal antibodies against IL-17 could be useful as a potential therapeutic remedy for future S-OIV H1N1 pandemics.
cytokine; acute lung injury; S-OIV H1N1
The TGF-b superfamily cytokine MIC-1/GDF15 circulates in all humans and when overproduced in cancer leads to anorexia/cachexia, by direct action on brain feeding centres. In these studies we have examined the role of physiologically relevant levels of MIC-1/GDF15 in the regulation of appetite, body weight and basal metabolic rate. MIC-1/GDF15 gene knockout mice (MIC-1−/−) weighed more and had increased adiposity, which was associated with increased spontaneous food intake. Female MIC-1−/− mice exhibited some additional alterations in reduced basal energy expenditure and physical activity, possibly owing to the associated decrease in total lean mass. Further, infusion of human recombinant MIC-1/GDF15 sufficient to raise serum levels in MIC-1−/− mice to within the normal human range reduced body weight and food intake. Taken together, our findings suggest that MIC-1/GDF15 is involved in the physiological regulation of appetite and energy storage.
Evaluating the effectiveness of existing nature reserve systems for the conservation of tropical forests is an urgent task to save the remaining biodiversity. Here, we tested the effectiveness of the reserve system on Hainan Island by conducting a three-way comparison of changes in forest area in locations within the reserves, adjacent to the reserves, and far outside of the reserves. We used a general linear model to control for the effects of covariates (historical forest area, elevation, slope, and distance to nearest roads), which may also be correlated with the changes in forest area, to better explain the effectiveness of the reserve system. From 2000 to 2010, the forest area inside Hainan’s nature reserve system showed an increase while adjacent unprotected areas and the wider, unprotected landscape both experienced deforestation. However, the simple inside-outside comparisons may overestimate the protective effect of the reserve system. Most nature reserves (>60%) showed increasing fragmentation. And the risk of rapid deforestation remained high at low elevations, where remaining forests tend to be easily logged and converted to commercial plantations. Future conservation efforts should pay more attention to those sites with less challenging environmental conditions.
AIM: To determine an optimal cutoff value for abnormal splenic artery diameter/proper hepatic artery diameter (S/P) ratio in cirrhosis-induced portal hypertension.
METHODS: Patients with cirrhosis and portal hypertension (n = 770) and healthy volunteers (n = 31) underwent volumetric computed tomography three-dimensional vascular reconstruction to measure the internal diameters of the splenic artery and proper hepatic artery to calculate the S/P ratio. The cutoff value for abnormal S/P ratio was determined using receiver operating characteristic curve analysis, and the prevalence of abnormal S/P ratio and associations between abnormal S/P ratio and major complications of portal hypertension were studied using logistic regression.
RESULTS: The receiver operating characteristic analysis showed that the cutoff points for abnormal splenic artery internal diameter and S/P ratio were > 5.19 mm and > 1.40, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.2%, 45.2%, 97.1%, and 6.6%, respectively. The prevalence of an abnormal S/P ratio in the patients with cirrhosis and portal hypertension was 83.4%. Patients with a higher S/P ratio had a lower risk of developing ascites [odds ratio (OR) = 0.708, 95%CI: 0.508-0.986, P = 0.041] and a higher risk of developing esophageal and gastric varices (OR = 1.483, 95%CI: 1.010-2.175, P = 0.044) and forming collateral circulation (OR = 1.518, 95%CI: 1.033-2.230, P = 0.034). After splenectomy, the portal venous pressure and maximum and mean portal venous flow velocities were reduced, while the flow rate and maximum and minimum flow velocities of the hepatic artery were increased (P < 0.05).
CONCLUSION: The prevalence of an abnormal S/P ratio is high in patients with cirrhosis and portal hypertension, and it can be used as an important marker of splanchnic hemodynamic disturbances.
Portal hypertension; Cirrhosis; Splenic artery internal diameter; Proper hepatic artery internal diameter; Complications; Splenectomy
Clostridium pasteurianum, an anaerobic bacterium able to utilize atmospheric free nitrogen for biosynthesis, has recently been proven to be a promising producer of chemicals and fuels, such as 1,3-propanediol and n-butanol. Here, we report the high-quality draft genome sequence of DSM 525, a type strain of C. pasteurianum.
Toll-like receptors (TLRs) are important initiators in native immune responses to microbial infections. TLR4 is up-regulated in response to H.pylori infection in gastric epithelial cells. However, the regulatory mechanisms for the expression of TLR4 in H.pylori infection have not been clearly defined. The aims of this study are to present the evidence that microRNA let-7b directly regulates TLR4 expression in human gastric epithelial cells, and subsequently influences the activation of NF-κB and the expression of the downstream genes in H.pylori infection.
The expression of let-7b was determined in gastric mucosa specimens and in two gastric epithelial cell lines using quantitative RT-PCR. The expression of TLR4 was determined by immunohistochemistry staining and RT-PCR. The potential target of let-7b was identified by luciferase reporter assay and Western blot. Let-7b mimics and inhibitors were used to examine the effects of let-7b on NF-κB activity. The expression of the downstream genes of NF-κB was also determined in cells infected with H.pylori 26695.
Let-7b was significantly decreased in gastric mucosa specimens and in gastric epithelial cell lines (AGS, GES-1) infected with H.pylori 26695 (cagA+). Let-7b was complementary to the 3′-UTR of TLR4 mRNA and regulated TLR4 expression via post-transcriptional suppression in gastric epithelium. Infection of H.pylori induced the expression of TLR4 and activated NF-κB in AGS and GES-1 cells. Overexpression of let-7b by mimics downregulated TLR4, and subsequently attenuated NF-κB, MyD88, NF-κB1/p50, RelA/p65. The expression of IL-8, COX-2 and CyclinD1 was inhibited in H.pylori infected cells with let-7b overexpression. Both TAK-242 (TLR4 inhibitor) and SN50 (NF-κB inhibitor) significantly inhibited the H.pylori induced downregulation of let-7b.
Let-7b targets at TLR4 mRNA, and regulates the activation of NF-κB and the expression of the downstream genes related to the inflammation and immune responses in H.pylori infection.
Since the KCNB1 encoding Kv2.1 channel accounts for the majority of Kv currents modulating insulin secretion by pancreatic islet beta-cells, we postulated that KCNB1 is a plausible candidate gene for genetic variation contributing to the variable compensatory secretory function of beta-cells in type-2 diabetes (T2D). We conducted two studies, a case-control study and a cross-section study, to investigate the association of common single-nucleotide polymorphisms (SNPs) in KCNB1 with T2D and its linking traits. In the case-control study, we first examined the association of 20 tag SNPs of KCNB1 with T2D in a population with 226 T2D patients and non-diabetic subjects (screening study). We then identified the association in an enlarged population of 412 T2D patients and non-diabetic subjects (replication study). In the cross-sectional study, we investigated the linkage between the candidate SNP rs1051295 and T2D by comparing beta-cell function and insulin sensitivity among rs1051295 genotypes in a general population of 1051 subjects at fasting and after glucose loading (oral glucose tolerance tests, OGTT) in 84 fasting glucose impaired subjects, and several T2D-related traits. We found that among the 19 available tag SNPs, only the KCNB1 rs1051295 was associated with T2D (P = 0.027), with the rs1051295 TT genotype associated with an increased risk of T2D compared with genotypes CC (P = 0.009). At fasting, rs1051295 genotype TT was associated with a 9.8% reduction in insulin sensitivity compared to CC (P = 0.008); along with increased plasma triglycerides (TG) levels (TT/CC: P = 0.046) and increased waist/hip (W/H) ratio (TT/CC: P = 0.013; TT/TC: P = 0.002). OGTT confirmed that genotype TT exhibited reduced insulin sensitivity by 16.3% (P = 0.030) compared with genotype TC+CC in a fasting glucose impaired population. The KCNB1 rs1051295 genotype TT in the Chinese Han population is associated with decreased insulin sensitivity and increased plasma TG and W/H ratio, which together contribute to an increased risk for T2D.
Corin is a transmembrane serine protease identified in the heart, where it converts natriuretic peptides from inactive precursors to mature active forms. Studies in animal models and patients with hypertension and heart disease demonstrate that corin is critical in maintaining normal blood pressure and cardiac function. Like many proteolytic enzymes, corin expression and activity are regulated. Cell biology experiments indicate that transcriptional control, intracellular protein trafficking, cell surface targeting, zymogen activation and ectodomain shedding are important mechanisms in regulating corin expression and activity in the heart. More recently, soluble corin was detected in human blood and its levels were found to be reduced in patients with heart failure (HF). These findings indicate that corin deficiency may be involved in the pathogenesis of HF and suggest that soluble corin may be used as a biomarker for the disease. In this review, we describe the function and regulation of corin and discuss recent studies of soluble corin in human blood and its potential use as a biomarker for HF.
The low lysine content of waxy maize cannot meet the nutritional requirements of humans, livestock, or poultry. In the present study, the high-lysine genes o2 and o16 were backcrossed into wx lines using the maize high-lysine inbreds TAIXI19 (o2o2) and QCL3021 (o16o16) as donors and the waxy maize inbred line QCL5019 (wxwx) as a receptor. In the triple-cross F1, backcross, and inbred generations, the SSR markers phi027 and phi112 within the wx and o2 genes and the SSR marker umc1121 linked to the o16 gene were used for foreground selection. Background selection of the whole-genome SSR markers was performed for the selected individuals. The grain lysine content was determined using the dye-binding lysine method. The waxiness of the grain was determined with the I2-KI staining and dual-wavelength spectrophotometric analysis. The BC2F2 generation included 7 plants of genotype wxwxo2o2O16_, 19 plants of genotype wxwxo16o16O2_, and 3 plants of genotype wxwxo2o2o16o16. In these seeds, the average amylopectin content was 96.67%, 96.87%, and 96.62%, respectively, which is similar to that of QCL5019. The average lysine content was 0.555%, 0.380%, and 0.616%, respectively, representing increases of 75.1%, 19.9%, 94.3%, respectively, over QCL5019. The average genetic background recovery rate of the BC2F3 families was 95.3%, 94.3%, 94.2%, respectively. Among these 3 wxwxo2o2O16O16 families, 4 wxwxo2o2O16o16 families, and 3 wxwxo2o2o16o16 families, the longest imported parent donor fragment was 113.35 cM and the shortest fragment was 11.75 cM. No significant differences in lysine content were found between the BC2F4 seeds and the BC2F3 seeds in these 10 families. This allowed us to increase the lysine content of waxy corn and produce seeds with excellent nutritional characteristics suitable for human consumption, animal feed, and food processing. This may be of significance in the breeding of high-quality corn and in improvement of the nutrition of humans, livestock, and poultry.
Despite a general repression of translation under hypoxia, cells selectively upregulate a set of hypoxia-inducible genes. Results from deep sequencing revealed that Let-7 and miR-103/107 are hypoxia-responsive microRNAs (HRMs) that are strongly induced in vascular endothelial cells. In silico bioinformatics and in vitro validation showed that these HRMs are induced by HIF1α and target argonaute 1 (AGO1), which anchors the microRNA-induced silencing complex (miRISC). HRM targeting of AGO1 resulted in the translational desuppression of VEGF mRNA. Inhibition of HRM or overexpression of AGO1 without the 3′ untranslated region decreased hypoxia-induced angiogenesis. Conversely, AGO1 knockdown increased angiogenesis under normoxia in vivo. In addition, data from tumor xenografts and human cancer specimens indicate that AGO1-mediated translational desuppression of VEGF may be associated with tumor angiogenesis and poor prognosis. These findings provide evidence for an angiogenic pathway involving HRMs that target AGO1 and suggest that this pathway may be a suitable target for anti- or proangiogenesis strategies.
The copper(I)-catalyzed azide-alkyne cycloaddition, the most widely recognized reaction of click chemistry, is accelerated by tris(triazolylmethyl)amine-based ligands. Here, we compared two new ligands in this family, BTTP and the corresponding sulfated ligand BTTPS, for three bioconjugation applications: (1) labeling of alkyne-tagged glycoproteins in crude cell lysates, (2) labeling of alkyne/azide-tagged glycoproteins on the surface of live mammalian cells, and (3) labeling of azides in surface proteins of live Escherichia coli. Though BTTPS exhibits faster kinetics than BTTP in accelerating the CuAAC in in vitro kinetic measurements, its labeling efficiency is slightly lower than BTTP in conjugating biomolecules bearing a significant amount of negative charges due to electrostatic repulsion. Nevertheless, the negative charge conferred by the sulfate at physiological conditions significantly reduced the cellular internalization of the coordinated Cu(I), thus making BTTPS-Cu(I) a better choice for live cell labeling.
click chemistry; copper; bioconjugation; glycoconjugates
AIM: To investigate the role of interleukin (IL)-17 in small bowel allograft rejection.
METHODS: We detected the expression of helper T cell 17 (Th17) cells in biopsy specimens from 3 cases of living small bowel transplantation in our department through immunofluorescence stain. We then established a rat heterotopic small bowel transplantation model. The rats were sacrificed on the 1st, 2nd, 3rd, 5th, and 7th d after small bowel transplantation. The degrees of transplantation rejection in rat intestine graft were examined through hematoxylin eosin (HE) stain, and the expression of Th17 cells in rat intestine graft were detected through immunofluorescence stain. In addition, the recipient rats undergoing intestinal transplantation were administrated with mouse-anti-rat IL-17 monoclonal antibody (mAb), and the survival of rats was analyzed. The recipient rats which received mouse-anti-rat IL-17 mAb treatment were sacrificed on the 1st, 2nd, 3rd, 5th, and 7th d after small bowel transplantation. The degrees of transplantation rejection and the expression of Th17 cells in rat intestine graft were detected through HE and immunofluorescence stain. The expression of IL-17, IL-1β, tumor necroses factor receptor-α (TNF-α), IL-6, and IL-8 in the intestine graft or serum were also detected.
RESULTS: The expressions of Th17 cells ran parallel with the degree of acute rejection in human intestine grafts. The intestine graft rejection of rats was aggravated with prolonged duration after intestinal transplantation, and the expressions of Th17 cells were also correlated with the degree of acute rejection in rat intestine grafts. Administration of mouse-anti-rat IL-17 mAb prolonged the survival of rats after small bowel transplantation (P < 0.001). Furthermore, we found that the administration of mouse-anti-rat IL-17 mAb significantly decreased the intensity of CD4+IL-17+ Th17 cells in intestine grafts on the 2nd, 3rd, 5th, and the 7th d (97.22 ± 4.05 vs 12.45 ± 2.02 on the 7th d, P < 0.0001), and suppressed the severity of acute rejection. The expression of IL-17 in the intestine graft declined after mouse-anti-rat IL-17 mAb administration on the 2nd, 3rd, 5th, and the 7th d (0.88 ± 0.03 vs 0.35 ± 0.02 on the 7th d, P < 0.0001). We also detected the IL-17 serum level and found that the IL-17 level reduced from the 1st d to the 7th d (6.52 ± 0.18 ng/mL vs 2.04 ± 0.15 ng/mL on the 7th d, P < 0.0001). No significant difference in the level of IL-17 mRNA in the intestine graft was identified between the two groups. The levels of IL-1β, TNF-α, IL-6, and IL-8 mRNA in the intestine graft after the administration of mouse-anti-rat IL-17 mAb were also tested. We found that on the 3rd, 5th, and 7th d after intestinal transplantation, administration of mouse-anti-rat IL-17 mAb significantly inhibited the levels of IL-1β (12.11 ± 1.16 vs 1.27 ± 0.15 on the 7th d, P < 0.001), TNF-α (27.37 ± 2.60 vs 1.06 ± 0.26 on the 7th d, P < 0.001), IL-6 (21.43 ± 1.79 vs 1.90 ± 0.32 on the 7th d, P < 0.001), and IL-8 (20.44 ± 1.44 vs 1.34 ± 0.20 on the 7th d, P < 0.001) mRNA in the intestine graft.
CONCLUSION: IL-17 may act as a promising and potent target for inhibiting acute rejection after small bowel transplantation.
Interleukin-17; Helper T cell 17; Small bowel transplantation; Acute rejection; Monoclonal antibody