Transplantation of stem cells into damaged hearts has had modest success as a treatment for ischemic heart disease. One of the limitations is the poor stem cell survival in the diseased microenvironment. Prolyl hydroxylase domain protein 2 (PHD2) is a cellular oxygen sensor that regulates two key transcription factors involved in cell survival and inflammation, hypoxia-inducible factor (HIF) and nuclear factor-κB (NF-κB).
We studied if and how PHD2 silencing in human adipose-derived stem cells (ADSCs) enhances their cardioprotective effects after transplantation into infarcted hearts.
Methods and Results
ADSCs were transduced with lentiviral shPHD2 to silence PHD2. ADSCs with or without shPHD2 were transplanted after myocardial infarction (MI) in mice. ADSCs reduced cardiomyocyte apoptosis, fibrosis and infarct size and improved cardiac function. shPHD2-ADSCs exerted significantly more protection. PHD2 silencing induced greater ADSCs survival, which was abolished by shHIF-1α. Conditioned medium (CM) from shPHD2-ADSCs decreased cardiomyocyte apoptosis. Insulin-like growth factor 1 (IGF-1) levels were significantly higher in the CM of shPHD2-ADSCs versus ADSCs, and depletion of IGF-1 attenuated the cardioprotective effects of shPHD2-ADSCs-CM. NF-κB activation was induced by shPHD2 to induce IGF-1 secretion via binding to IGF-1 gene promoter.
PHD2 silencing promotes ADSCs survival in MI hearts and enhances their paracrine function to protect cardiomyocytes. The pro-survival effect of shPHD2 on ADSCs is HIF-1α dependent and the enhanced paracrine function of shPHD2-ADSCs is associated with NF-κB-mediated IGF-1 up-regulation. PHD2 silencing in stem cells may be a novel strategy for enhancing the effectiveness of stem cell therapy after MI.
Myocardial infarction; stem cell; survival; paracrine effect; cardiomyocyte
Recent studies have demonstrated that transplantation of adipose-derived stem cell (ADSC) can improve cardiac function in animal models of myocardial infarction (MI). However, the mechanisms underlying the beneficial effect are not fully understood. In this study, we characterized the paracrine effect of transplanted ADSC and investigated its relative importance versus direct differentiation in ADSC transplantation mediated cardiac repair.
MI was experimentally induced in mice by ligation of the left anterior descending coronary artery. Either human ADSC, conditioned medium (CM) collected from the same amount of ADSC or control medium was injected into the peri-infarct region immediately after MI. Compared with the control group, both ADSC and ADSC-CM significantly reduced myocardial infarct size and improved cardiac function. The therapeutic efficacy of ADSC was moderately superior to ADSC-CM. ADSC-CM significantly reduced cardiomyocyte apoptosis in the infarct border zone, to a similar degree with ADSC treatment. ADSC enhanced angiogenesis in the infarct border zone, but to a stronger degree than that seen in the ADSC-CM treatment. ADSC was able to differentiate to endothelial cell and smooth muscle cell in post-MI heart; these ADSC-derived vascular cells amount to about 9% of the enhanced angiogenesis. No cardiomyocyte differentiated from ADSC was found.
ADSC-CM is sufficient to improve cardiac function of infarcted hearts. The therapeutic function of ADSC transplantation is mainly induced by paracrine-mediated cardioprotection and angiogenesis, while ADSC differentiation contributes a minor benefit by being involved in angiogenesis.
Highlights 1 ADSC-CM is sufficient to exert a therapeutic potential. 2. ADSC was able to differentiate to vascular cells but not cardiomyocyte. 3. ADSC derived vascular cells amount to about 9% of the enhanced angiogenesis. 4. Paracrine effect is the major mechanism of ADSC therapeutic function for MI.
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
Adult cystic fibrosis (CF) patients are an expanding cohort that is taken care of in a variety of hospital settings including adult centers located within pediatric institutions. This study compared costs and discharge rates among adult CF patient hospitalizations in terms of location of hospitalization.
The 2007 Nationwide Inpatient Sample was utilized to identify adult CF patient admission data on patients aged 18–44. Data were separated into pediatric and adult facilities based on percentage discharge rate for patients >18. Primary outcomes measures were length of stay (LOS) and total hospital charges. Secondary predictors were geographic, primary payer, and co-morbidity effects on LOS and total hospital charges.
LOS was higher for adult CF patient admissions in pediatric facilities compared to adult facilities by a mean of 2.5 days. Mean total hospital charges were not significantly different. Adult hospitals in the Western U.S. had a mean total charge more than $50,000 greater than any region in the U.S. Self-pay patients had significantly fewer hospital days and charges across all hospital types. Adult facilities had 7% more CF patients discharged home with home healthcare use. Depressed CF patients had longer LOS by 1.5 days regardless of facility type.
LOS for adult CF inpatient admissions was significantly lower in adult facilities compared to pediatric facilities without a significant difference in hospital charges and is influenced by geographic hospital location. Depressed patients had longer lengths of stay regardless of facility type. Self-insured adult CF patients have a significant reduction in LOS and hospital charges when compared to all other payers regardless of hospital type.
healthcare utilization; socioeconomic factors; geographic factors
Acid-sensing ion channels (ASICs), a novel class of ligand-gated cation channels activated by protons, are highly expressed in peripheral sensory and central neurons. Activation of ASICs may play an important role in physiological processes such as nociception, mechanosensation, and learning–memory, and in the pathology of neurological conditions such as brain ischemia. Modulation of the activities of ASICs is expected to have a significant influence on the roles that these channels can play in both physiological and/or pathological processes. Here we show that the divalent cation Zn2+, an endogenous trace element, dose-dependently inhibits ASIC currents in cultured mouse cortical neurons at nanomolar concentrations. With ASICs expressed in Chinese hamster ovary cells, Zn2+ inhibits currents mediated by homomeric ASIC1a and heteromeric ASIC1a–ASIC2a channels, without affecting currents mediated by homomeric ASIC1β, ASIC2a, or ASIC3. Consistent with ASIC1a-specific modulation, high-affinity Zn2+ inhibition is absent in neurons from ASIC1a knock-out mice. Current-clamp recordings and Ca2+-imaging experiments demonstrated that Zn2+ inhibits acid-induced membrane depolarization and the increase of intracellular Ca2+. Mutation of lysine-133 in the extracellular domain of the ASIC1a subunit abolishes the high-affinity Zn2+ inhibition. Our studies suggest that Zn2+ may play an important role in a negative feedback system for preventing overexcitation of neurons during normal synaptic transmission and ASIC1a-mediated excitotoxicity in pathological conditions.
acid-sensing ion channels; ASICs; zinc inhibition; excitability; patch clamp; neuron
To accurately measure the end-expiratory pulmonary artery wedge pressure (PAWP) with the “expiration holding” function on the ventilator and the “pulmonary artery wedge pressure review” software on the monitor.
Materials and methods
Fifty prospective measurements were made on 12 patients undergoing pulmonary artery catheter and mechanical ventilation. All measurements were divided into <8 mmHg or ≥8 mmHg subgroups according to respiratory variability, and they were then subdivided into either an airway pressure display measurement group (AM group) or an expiration holding (EH) group for comparison.
In all measurements, the two groups showed similar levels of accuracy; however, for the time spent for measurement, the EH group was much faster than the airway pressure display measurement group (P<0.001). Additionally, the EH group was associated with lower medical costs.
The expiration holding approach measured the PAWP more accurately, more quickly, and with reduced costs in comparison to the airway pressure display approach.
expiration holding; pulmonary artery wedge pressure; eePAWP; mechanical ventilation; pulmonary artery catheter
To assess the humoral immune response to low-dose AS03-adjuvanted and standard-dose nonadjuvanted 2009 pandemic H1N1 influenza A vaccine in HIV-infected aviremic individuals receiving antiretroviral therapy and in uninfected individuals.
A three-arm study.
Two clinics: one at the National Institutes of Health in Bethesda, Maryland, USA; and the other at the Maple Leaf Medical Clinic in Toronto, Ontario, Canada.
HIV-infected and HIV-uninfected adults.
Single intramuscular 15µg dose of the monovalent inactivated 2009 pandemic H1N1 influenza A vaccine without adjuvant or 3.75µg dose of the same strain with adjuvant AS03.
Immunogenicity, as measured by hemagglutination inhibition (HAI) antibody titers and vaccine-specific memory B-cell responses.
A total of 74 participants were enrolled. Twenty-one HIV-infected individuals received the low-dose adjuvanted 2009 pandemic H1N1 influenza A vaccine. Twenty-nine HIV-infected and 24 HIV-uninfected individuals received the standard-dose nonadjuvanted vaccine. There were no significant differences in antibody responses at 9 weeks postvaccination among the three groups studied. However, the IgG memory B-cell response against the vaccine was significantly higher in the HIV-infected group that received the low-dose adjuvanted vaccine when compared to the HIV-infected and uninfected groups that received the standard-dose nonadjuvanted vaccine. Conclusions remained unchanged after regression adjustment for age, gender, CD4+ T-cell count, and baseline HAI titer.
These data suggest that adjuvants could be used to expand coverage through dose sparing and improve humoral immune responses in immunocompromised individuals.
adjuvants; antibody response; HIV infection; memory B-cell response; pandemic influenza; vaccination
We study the detection of mutations, sequencing errors, and homologous recombination events (HREs) in a set of closely related microbial genomes. We base the model on single nucleotide polymorphisms (SNPs) and break the genomes into blocks to handle the rearrangement problem. Then we apply a dynamic programming algorithm to model whether changes within each block are likely a result of mutations, sequencing errors, or HREs. Results from simulation experiments show that we can detect 31%–61% of HREs and the precision of our detection is about 48%–90% depending on the rates of mutation and missing data. The HREfinder software for predicting HREs in a set of whole genomes is available as open source (http://sourceforge.net/projects/hrefinder/).
Intersectins (Itsn) are conserved EH and SH3 domain containing adaptor proteins. In Drosophila melanogaster, ITSN is required to regulate synaptic morphology, to facilitate efficient synaptic vesicle recycling and for viability. Here, we report our genetic analysis of Caenorhabditis elegans intersectin. In contrast to Drosophila, C. elegans itsn-1 protein null mutants are viable and display grossly normal locomotion and development. However, motor neurons in these mutants show a dramatic increase in large irregular vesicles and accumulate membrane-associated vesicles at putative endocytic hotspots, approximately 300 nm from the presynaptic density. This defect occurs precisely where endogenous ITSN-1 protein localizes in wild-type animals and is associated with a significant reduction in synaptic vesicle number and reduced frequency of endogenous synaptic events at neuromuscular junctions (NMJs). ITSN-1 forms a stable complex with EHS-1 (Eps15) and is expressed at reduced levels in ehs-1 mutants. Thus, ITSN-1 together with EHS-1, coordinate vesicle recycling at C. elegans NMJs. We also found that both itsn-1 and ehs-1 mutants show poor viability and growth in a Disabled (dab-1) null mutant background. These results show for the first time that intersectin and Eps15 proteins function in the same genetic pathway, and appear to function synergistically with the clathrin-coat-associated sorting protein, Disabled, for viability.
Dab; endocytosis; Eps15; intersectin; synaptic vesicle
Sequential adsorption of poly(styrene sulfonate) (PSS) and proteases in porous nylon yields enzymatic membrane reactors for limited protein digestion. Although a high local enzyme density (~30 mg/cm3) and small pore diameters in the membrane lead to digestion in < 1 s, the low membrane thickness (170 μm) affords control over residence times at the ms level to limit digestion. Apomyoglobin digestion demonstrates that peptide lengths increase as the residence time in the membrane decreases. Moreover, electron transfer dissociation (ETD) tandem mass spectrometry (MS/MS) on a large myoglobin proteolytic peptide (8 kD) provides a resolution of 1–2 amino acids. Under denaturing conditions, limited membrane digestion of bovine serum albumin (BSA) and subsequent ESI-Orbitrap MS analysis reveal large peptides (3 kD–10 kD) that increase the sequence coverage from 53 % (2-s digestion) to 82 % (0.05-s digestion). With this approach we also performed membrane-based limited proteolysis of a large Arabidopsis GTPase, ROOT HAIR DEFECTIVE 3 (RHD3), and showed suitable probing for labile regions near the C-terminus to suggest what protein reconstruction might make RHD3 more suitable for crystallization.
To evaluate the feasibility, effectiveness, and safety of reinnervation of the bilateral posterior cricoarytenoid (PCA) muscles using the left phrenic nerve in patients with bilateral vocal fold paralysis.
Forty-four patients with bilateral vocal fold paralysis who underwent reinnervation of the bilateral PCA muscles using the left phrenic nerve were enrolled in this study. Videostroboscopy, perceptual evaluation, acoustic analysis, maximum phonation time, pulmonary function testing, and laryngeal electromyography were performed preoperatively and postoperatively. Patients were followed-up for at least 1 year after surgery.
Videostroboscopy showed that within 1 year after reinnervation, abductive movement could be observed in the left vocal folds of 87% of patients and the right vocal folds of 72% of patients. Abductive excursion on the left side was significantly larger than that on the right side (P < 0.05); most of the vocal function parameters were improved postoperatively compared with the preoperative parameters, albeit without a significant difference (P > 0.05). No patients developed immediate dyspnea after surgery, and the pulmonary function parameters recovered to normal reference value levels within 1 year. Postoperative laryngeal electromyography confirmed successful reinnervation of the bilateral PCA muscles. Eighty-seven percent of patients in this series were decannulated and did not show obvious dyspnea after physical activity. Those who were decannulated after subsequent arytenoidectomy were not included in calculating the success rate of decannulation.
Reinnervation of the bilateral PCA muscles using the left phrenic nerve can restore inspiratory vocal fold abduction to a physiologically satisfactory extent while preserving phonatory function at the preoperative level without evident morbidity.
Simvastatin exerts pleiotropic effects on cardiovascular system. However, its effect on non-alcoholic fatty liver disease, especially the liver fibrosis, remains obscure. We aimed to clarify the relationship between simvastatin and liver fibrosis both in vivo and in vitro.
A High-fat diet was given to establish rat models with non-alcoholic steatohepatitis (NASH)-related liver fibrosis and simvastatin (4mg·kg-1·d-1) was administrated intragastrically until hepatic histological findings confirmed the appearance of fibrosis. Human hepatic stellate cell (HSC) line lx-2 cells were cultured in an adipogenic differentiating mixture (ADM) and then were treated with transforming growth factorβ1 (TGF-β1), served as a positive control, simvastatin, TGF-β1 plus simvastatin, Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME, a inhibitor of nitric oxide synthase), and L-NAME plus simvastatin, respectively. The expressions of endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and Collagen І as well as cellular α-smooth muscle actin (α-SMA) were measured by real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) and Western blot in liver tissue and HSC.
With the progress of NASH-related fibrosis, hepatic mRNA and protein expressions of iNOS, α-SMA, and Collagen І were increased while those of eNOS were decreased. Compared with model rats in 24th week group, rats in simvastatin group had less expressions of iNOS, α-SMA, and Collagen І and more expressions of eNOS. In vitro, LX-2 cells acquired quiescent phenotype when cultured in ADM, and TGF-β1 could activate the quiescent HSC. Simvastatin inhibited LX-2 cells activation due to TGF-β1 or L-NAME by increasing the expression of eNOS and decreasing the expression of iNOS.
Simvastatin improves the prognosis of NASH-related fibrosis by increasing the expression of eNOS, decreasing the expression of iNOS, and inhibiting the activation of HSC.
Osteoporotic vertebral compressed fractures (VCFs) are the most common osteoporotic fractures. Although percutaneous vertebroplasty (PVP) reportedly relieves pain and improves function, a recent pooled analysis from two multicenter randomized controlled trials concluded the improvement in pain and disability treated with PVP was similar to those with sham surgery.
Using meta-analysis we therefore asked whether compared with either nonoperative therapy or a sham injection for patients with VCF, PVP would (1) better relieve pain, (2) provide greater improvement in pain-related disability, and (3) increase the recurrence of vertebral fractures.
We searched PubMed, EMBASE, Medline, and the Cochrane library using the keywords “vertebroplasty AND osteoporosis OR fracture”. We included nine of the 469 articles identified. Using a random effects model, we calculated the weighted mean differences to evaluate the pain reduction at different times as the primary outcome. Pain-related disability was assessed by a quality of life (QOL) measure. Improvement of QOL and recurrence of vertebral fractures were the secondary outcomes. We used subgroup analysis to reinvestigate pain relief and function improvement of PVP based on two different controls: nonoperative therapy and sham injection. The total number of patients was 886.
Pain scoring was similar between the PVP group and the sham injection group at 1 to 29 days and 90 days. However, compared with nonoperative therapy, PVP reduced pain at all times studied. QOL in the PVP group was improved or tended to be improved compared with QOL for both control groups. The risk of new fractures was similar between the PVP groups and both control groups.
Different control groups may have accounted for the different conclusions in the literature regarding the ability of PVP to relieve pain and restore function recovery. Compared with nonoperative treatment PVP relieved pain better and improved QOL. PVP did not increase the risk of new fractures.
Level of Evidence
Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.
Endocannabinoid-mediated long-term depression of inhibitory synaptic transmission (I-LTD) in the ventral tegmental area (VTA) is implicated in cocaine-induced inhibitory synaptic plasticity and behavioral effects. It remains poorly understood, however, how this I-LTD is regulated and whether this regulation affects cocaine-seeking behavior. I-LTD requires cyclic adenosine 3′, 5′-monophosphate (cAMP)-dependent protein kinase A (PKA) signaling, raising the possibility that modulators of cAMP/PKA signaling may regulate I-LTD and the reinforcement behavior. Phosphodiesterase (PDE) 4 hydrolyses cAMP and terminates cAMP/PKA signaling. Here, we report that selective PDE4 inhibitors rolipram and Ro 20-1724 blocked I-LTD and acute depression of inhibitory postsynaptic currents (IPSCs) induced by D2 dopamine receptor and cannabinoid CB1 receptor agonists in VTA dopamine neurons. We also show that intra-VTA microinjections of PDE4 inhibitor rolipram impaired the acquisition, but not the expression, of conditioned place preference (CPP) to cocaine. Systemic administration of rolipram also increased cAMP response element-binding protein (CREB) phosphorylation and activation in the VTA. Together, our results suggest that blockade of cocaine-induced inhibitory synaptic plasticity (I-LTD) and enhancement of CREB activation are two putative cellular mechanisms by which PDE4 inhibition impairs the acquisition of cocaine CPP.
phosphodiesterase 4 (PDE4); endocannabinoid; long-term depression of inhibitory synaptic transmission (I-LTD); conditioned place preference (CPP); cAMP response element-binding protein (CREB); addiction and substance abuse; cAMP; cannabinoids; endocannabinoid; I-LTD; neurophysiology; phosphodiesterase 4; second messengers; synaptic plasticity
The pituitary gland is composed of hormone-producing cells essential for homeostasis and reproduction. Pituitary cells are sensitive to endocrine feedback in the adult and can have altered hormonal secretion from exposure to the endocrine disruptor bisphenol A (BPA). BPA is a prevalent plasticizer used in food and beverage containers, leading to widespread human exposure. Although prenatal exposure to BPA can impact reproductive function in the adult, the effects of BPA on the developing pituitary are unknown. We hypothesized that prenatal exposure to low doses of BPA impacts gonadotroph cell number or parameters of hormone synthesis. To test this, pregnant mice were administered 0.5 μg/kg/day of BPA, 50 μg/kg/day of BPA, or vehicle beginning on Embryonic Day 10.5. At parturition, pituitaries from female offspring exposed in utero to either dose of BPA had increased proliferation, as assessed by mKi67 mRNA levels and immunohistochemistry. Coincidently, gonadotroph number also increased in treated females. However, we observed a dichotomy between mRNA levels of Lhb and Fshb. Female mice exposed to 0.5 μg/kg/day BPA had increased mRNA levels of gonadotropins and the gonadotropin-receptor hormone (GNRH) receptor (Gnrhr), which mediates GNRH regulation of gonadotropin production and release. In contrast, mice treated with 50 μg/kg/day of BPA had decreased gonadotropin mRNA levels, Gnrhr and Nr5a1, a transcription factor required for gonadotroph differentiation. No other pituitary hormones were altered on the day of birth in response to in utero BPA exposure, and male pituitaries showed no change in the parameters tested. Collectively, these results show that prenatal exposure to BPA affects pituitary gonadotroph development in females.
Developmental exposure to low doses of bisphenol A increases proliferation and alters gonadotroph differentiation in the pituitary.
anterior pituitary; bisphenol A (BPA); development; developmental biology; endocrine disruptors; environmental contaminants and toxicants; follicle-stimulating hormone (FSH); gonadotrophs; gonadotropins; luteinizing hormone (LH); pituitary
The enzyme 6-phospho-β-glucosidase is an important member of the glycoside hydrolase family 1 (GH1). However, its catalytic mechanisms, especially the key residues determining substrate specificity and affinity, are poorly understood. A metagenome-derived gene sequence, encoding a novel 6-phospho-β-glucosidase designated Pbgl25-217, was isolated and characterized. The optimal conditions for enzymatic activity were 37°C and pH 7; Ca2+, Mg2+, and Mn2+ stabilized the activity of Pbgl25-217, whereas Ni2+, Fe2+, Zn2+, Cu2+, and Fe3+ inhibited its activity. The Km and Vmax of Pbgl25-217 were 4.8 mM and 1,987.0 U mg−1, respectively. Seven conserved residues were recognized by multiple alignments and were tested by site-directed mutagenesis for their functions in substrate recognition and catalytic reaction. The results suggest that residues S427, Lys435, and Tyr437 act as “gatekeepers” in a phosphate-binding loop and play important roles in phosphate recognition. This functional identification may provide insights into the specificity of 6-phospho-β-glycosidases in GH1 and be useful for designing further directed evolution.
Laser ablation for varicose veins is a common practice, and postoperative complications may happen. A retained foreign body could be left accidently in the treated leg. It is rarely reported in literature. We herein describe two cases of retained foreign body during the laser ablation for varicose veins. One patient with varicose veins received laser therapy 5 years earlier, and had experienced discomfort and pain. After investigation, an overlooked sheath fragment was removed surgically from the leg. Another patient with varicose veins had discomfort after laser ablation for 8 days, and has been asymptomatic after the removal of the retained foreign body in the leg. The essential preventive approach include to pinpoint the site of the tip of fiberoptic laser fiber and pull 1 to 2 cm of the sheath out of the patient, then withdrawal the fiberoptic fiber and sheath simultaneously. A white flash light in the trunk of the fiberoptic laser fiber is an important warning signal of an erroneous manipulation during the operation. The surgeon should routinely check the intact sheath and fiberoptic fiber after laser ablation. In conclusion, retained foreign body can be prevented by following some practical tips during laser ablation.
Laser ablation; Varicose veins; Retained foreign body
Stem cell therapy has emerged as a promising strategy for cardiac and
vascular repair. The ultimate goal is to rebuild functional myocardium by
transplanting exogenous stem cells or by activating native stem cells to induce
endogenous repair. CS/PCs (cardiac stem/progenitor cells) are one type of adult
stem cell with the potential to differentiate into cardiac lineages
(cardiomyocytes, smooth muscle cells and endothelial cells). iPSCs (induced
pluripotent stem cells) also have the capacity to differentiate into necessary
cells to rebuild injured cardiac tissue. Both types of stem cells have brought
promise for cardiac repair. The present review summarizes recent advances in
cardiac cell therapy based on these two cell sources and discusses the
advantages and limitations of each candidate. We conclude that, although both
types of stem cells can be considered for autologous transplantation with
promising outcomes in animal models, CS/PCs have advanced more in their clinical
application because iPSCs and their derivatives possess inherent obstacles for
clinical use. Further studies are needed to move cell therapy forward for the
treatment of heart disease.
cardiac stem/progenitor cell; endogenous activation; induced pluripotent stem cell; heart failure; regeneration; transplantation
Sturgeon (Acipenser sturio Linnaeus) skin contains high amount of nutrients including unsaturated fatty acids and collagen. A pepsin-assisted extraction procedure was developed and optimized for the extraction of collagen from Chinese sturgeon (Acipenser sturio Linnaeus) skins.
To determine the optimum conditions with the maximum yield of the pepsin-soluble collagen (PSC) extraction.
Materials and Methods:
The conditions of the extraction were optimized using response surface methodology. The Box–Behnken design was used to evaluate the effects of the three independent variables (extraction time, enzyme concentration, and solid–liquid ratio) on the PSC yield of the sturgeon skin.
The optimal conditions were: solid–liquid ratio of 1:11.88, enzyme concentration of 2.42%, and extraction time of 6.45 h. The maximum yield of 86.69% of PSC was obtained under the optimal conditions. This value was not significantly different from the predicted value (87.4%) of the RSM (P < 0.05).
The results of this study indicated that the production of PSC from sturgeon skin is feasible and beneficial. The patterns of sodium dodecyl sulfate-polyacrylamide gel electrophoretic patterns (SDS-PAGE) indicated that the sturgeon skin contains type I collagen, which is made of α-chain and β-chain. The infrared spectra of the collagens also indicated that pepsin hydrolysis does not affect the secondary structure of collagen, especially triple-helical structure.
Extraction; pepsin-soluble collagen; response surface methodology; sturgeon skin; SDS-PAGE
Heme oxygenase-1 (HO-1) has been implicated in cardiac dysfunction, oxidative stress, inflammation, apoptosis and autophagy associated with heart failure, and atherosclerosis, in addition to its recognized role in metabolic syndrome and diabetes. Numerous studies have presented contradictory findings about the role of HO-1 in diabetic cardiomyopathy (DCM). In this study, we explored the role of HO-1 in myocardial dysfunction, myofibril structure, oxidative stress, inflammation, apoptosis and autophagy using a streptozotocin (STZ)-induced diabetes model in mice systemically overexpressing HO-1 (Tg-HO-1) or mutant HO-1 (Tg-mutHO-1). The diabetic mouse model was induced by multiple peritoneal injections of STZ. Two months after injection, left ventricular (LV) function was measured by echocardiography. In addition, molecular biomarkers related to oxidative stress, inflammation, apoptosis and autophagy were evaluated using classical molecular biological/biochemical techniques. Mice with DCM exhibited severe LV dysfunction, myofibril structure disarray, aberrant cardiac oxidative stress, inflammation, apoptosis, autophagy and increased levels of HO-1. In addition, we determined that systemic overexpression of HO-1 ameliorated left ventricular dysfunction, myofibril structure disarray, oxidative stress, inflammation, apoptosis and autophagy in DCM mice. Furthermore, serine/threonine-specific protein kinase (Akt) and AMP-activated protein kinase (AMPK) phosphorylation is normally inhibited in DCM, but overexpression of the HO-1 gene restored the phosphorylation of these kinases to normal levels. In contrast, the functions of HO-1 in DCM were significantly reversed by overexpression of mutant HO-1. This study underlines the unique roles of HO-1, including the inhibition of oxidative stress, inflammation and apoptosis and the enhancement of autophagy, in the pathogenesis of DCM.