Molecular basis of functional myogenic specification of Bona Fide multipotent adult cardiac stem cells

Ischemic Heart Disease (IHD) remains the developed world’s number one killer. The improved survival from Acute Myocardial Infarction (AMI) and the progressive aging of western population brought to an increased incidence of chronic Heart Failure (HF), which assumed epidemic proportions nowadays. Except for heart transplantation, all treatments for HF should be considered palliative because none of the current therapies can reverse myocardial degeneration responsible for HF syndrome. To stop the HF epidemic will ultimately require protocols to reduce the progressive cardiomyocyte (CM) loss and to foster their regeneration. It is now generally accepted that mammalian CMs renew throughout life. However, this endogenous regenerative reservoir is insufficient to repair the extensive damage produced by AMI/IHD while the source and degree of CM turnover remains strongly disputed. Independent groups have convincingly shown that the adult myocardium harbors bona-fide tissue specific cardiac stem cells (CSCs). Unfortunately, recent reports have challenged the identity and the endogenous myogenic capacity of the c-kit expressing CSCs. This has hampered progress and unless this conflict is settled, clinical tests of repair/regenerative protocols are unlikely to provide convincing answers about their clinical potential. Here we review recent data that have eventually clarified the specific phenotypic identity of true multipotent CSCs. These cells when coaxed by embryonic cardiac morphogens undergo a precisely orchestrated myogenic commitment process robustly generating bona-fide functional cardiomyocytes. These data should set the path for the revival of further investigation untangling the regenerative biology of adult CSCs to harness their potential for HF prevention and treatment.     

Depression in Working Adults: Comparing the Costs and Health Outcomes of Working When Ill

Objective

Working through a depressive illness can improve mental health but also carries risks and costs from reduced concentration, fatigue, and poor on-the-job performance. However, evidence-based recommendations for managing work attendance decisions, which benefit individuals and employers, are lacking. Therefore, this study has compared the costs and health outcomes of short-term absenteeism versus working while ill (“presenteeism”) amongst employed Australians reporting lifetime major depression.

Methods

Cohort simulation using state-transition Markov models simulated movement of a hypothetical cohort of workers, reporting lifetime major depression, between health states over one- and five-years according to probabilities derived from a quality epidemiological data source and existing clinical literature. Model outcomes were health service and employment-related costs, and quality-adjusted-life-years (QALYs), captured for absenteeism relative to presenteeism, and stratified by occupation (blue versus white-collar).

Results

Per employee with depression, absenteeism produced higher mean costs than presenteeism over one- and five-years ($42,573/5-years for absenteeism, $37,791/5-years for presenteeism). However, overlapping confidence intervals rendered differences non-significant. Employment-related costs (lost productive time, job turnover), and antidepressant medication and service use costs of absenteeism and presenteeism were significantly higher for white-collar workers. Health outcomes differed for absenteeism versus presenteeism amongst white-collar workers only.

Conclusions

Costs and health outcomes for absenteeism and presenteeism were not significantly different; service use costs excepted. Significant variation by occupation type was identified. These findings provide the first occupation-specific cost evidence which can be used by clinicians, employees, and employers to review their management of depression-related work attendance, and may suggest encouraging employees to continue working is warranted.     

Dopamine Genetic Risk Score Predicts Depressive Symptoms in Healthy Adults and Adults with Depression

Background

Depression is a common source of human disability for which etiologic insights remain limited. Although abnormalities of monoamine neurotransmission, including dopamine, are theorized to contribute to the pathophysiology of depression, evidence linking dopamine-related genes to depression has been mixed. The current study sought to address this knowledge-gap by examining whether the combined effect of dopamine polymorphisms was associated with depressive symptomatology in both healthy individuals and individuals with depression.

Methods

Data were drawn from three independent samples: (1) a discovery sample of healthy adult participants (n = 273); (2) a replication sample of adults with depression (n = 1,267); and (3) a replication sample of healthy adult participants (n = 382). A genetic risk score was created by combining functional polymorphisms from five genes involved in synaptic dopamine availability (COMT and DAT) and dopamine receptor binding (DRD1, DRD2, DRD3).

Results

In the discovery sample, the genetic risk score was associated with depressive symptomatology (β = −0.80, p = 0.003), with lower dopamine genetic risk scores (indicating lower dopaminergic neurotransmission) predicting higher levels of depression. This result was replicated with a similar genetic risk score based on imputed genetic data from adults with depression (β = −0.51, p = 0.04). Results were of similar magnitude and in the expected direction in a cohort of healthy adult participants (β = −0.86, p = 0.15).

Conclusions

Sequence variation in multiple genes regulating dopamine neurotransmission may influence depressive symptoms, in a manner that appears to be additive. Further studies are required to confirm the role of genetic variation in dopamine metabolism and depression.     

Hsp110 Is a Bona Fide Chaperone Using ATP to Unfold Stable Misfolded Polypeptides and Reciprocally Collaborate with Hsp70 to Solubilize Protein Aggregates

Structurally and sequence-wise, the Hsp110s belong to a subfamily of the Hsp70 chaperones. Like the classical Hsp70s, members of the Hsp110 subfamily can bind misfolding polypeptides and hydrolyze ATP. However, they apparently act as a mere subordinate nucleotide exchange factors, regulating the ability of Hsp70 to hydrolyze ATP and convert stable protein aggregates into native proteins. Using stably misfolded and aggregated polypeptides as substrates in optimized in vitro chaperone assays, we show that the human cytosolic Hsp110s (HSPH1 and HSPH2) are bona fide chaperones on their own that collaborate with Hsp40 (DNAJA1 and DNAJB1) to hydrolyze ATP and unfold and thus convert stable misfolded polypeptides into natively refolded proteins. Moreover, equimolar Hsp70 (HSPA1A) and Hsp110 (HSPH1) formed a powerful molecular machinery that optimally reactivated stable luciferase aggregates in an ATP- and DNAJA1-dependent manner, in a disaggregation mechanism whereby the two paralogous chaperones alternatively activate the release of bound unfolded polypeptide substrates from one another, leading to native protein refolding.     

Cyclin D1 Is a Bona Fide Target Gene of NFATc1 and Is Sufficient in the Mediation of Injury-induced Vascular Wall Remodeling

Platelet-derived growth factor BB induced cyclin D1 expression in a time- and nuclear factor of activated T cells (NFAT)-dependent manner in human aortic smooth muscle cells (HASMCs), and blockade of NFATs prevented HASMC DNA synthesis and their cell cycle progression from G₁ to S phase. Selective inhibition of NFATc1 by its small interfering RNA also blocked HASMC proliferation and migration. Characterization of the cyclin D1 promoter revealed the presence of several NFAT binding sites, and the site at nucleotide −1333 was found to be sufficient in mediating platelet-derived growth factor BB-induced cyclin D1 promoter-luciferase reporter gene activity. In addition to its role in cell cycle progression, cyclin D1 mediated HASMC migration in an NFATc1-dependent manner. Balloon injury-induced cyclin D1-CDK4 activity requires NFAT activation, and adenovirus-mediated transduction of cyclin D1 was found to be sufficient to overcome the blockade effect of NFATs by VIVIT on balloon injury-induced vascular wall remodeling events, including smooth muscle cell migration from the medial to luminal region, their proliferation in the intimal region, and neointima formation. Together, these results provide more mechanistic evidence for the role of NFATs, particularly NFATc1, in the regulation of HASMC proliferation and migration as well as vascular wall remodeling. NFATc1 could be a potential therapeutic target against the renarrowing of artery after angioplasty.     

The Z Protein of the New World Arenavirus Tacaribe Virus Has Bona Fide Budding Activity That Does Not Depend on Known Late Domain Motifs

The arenavirus small RING finger Z protein has been shown to be the main driving force of budding for several arenaviruses. This Z budding activity was found to be mediated by the late (L)-domain motifs P(T/S)AP and PPXY, located at the C terminus of Z. Here, we show that the Z protein of Tacaribe virus (TACV), a New World arenavirus, buds efficiently from cells despite lacking the canonical L-domain motifs P(T/S)AP and PPXY. Likewise, potential L-domain motifs ASAP and YLCL present in TACV Z did not exhibit any significant contribution to TACV Z budding activity. Budding of TACV Z was Tsg101 independent but required the activity of Vps4A/B. These results indicate that TACV Z utilizes a budding mechanism distinct from that reported for other arenaviruses.Arenaviruses are enveloped viruses with a bisegmented, negative-strand (NS) RNA genome and a life cycle restricted to the cell cytoplasm (1). Each RNA segment uses an ambisense coding strategy to direct the expression of two genes that are in opposite orientations and separated by a noncoding intergenic region. The large segment (7.2 kb) encodes the late (L) protein, an RNA-dependent RNA polymerase, and the small RING finger protein Z, which is the counterpart of the matrix (M) protein found in many enveloped NS RNA viruses. The small segment (3.5 kb) encodes the viral nucleoprotein (NP) and the glycoprotein precursor (GPC). The GPC is processed by the cellular protease S1P into GP1 and GP2 (13). Trimers of GP1/GP2 form the spikes that decorate the virus surface and mediate cell entry via receptor-mediated endocytosis (12).Arenaviruses merit significant interest both as tractable experimental model systems to study acute and persistent viral infections (18, 28) and as clinically important human pathogens. The Old World virus Lassa virus (LASV) and several New World (NW) arenaviruses cause hemorrhagic fever (HF) disease in humans, posing a serious public health problem (1). LASV is estimated to infect several hundred thousand individuals yearly in the regions of West Africa where it is endemic, resulting in a high number of Lassa fever (LF) cases associated with significant mortality and high morbidity. Notably, increased travel to and from regions of endemicity has led to the importation of LF into metropolitan areas, where the virus is not endemic, around the globe (11). Likewise, the NW arenavirus Junin virus causes Argentine HF, a severe illness with hemorrhagic and neurological manifestations and a fatality rate of 15 to 30% (7, 22, 27), while the NW Machupo and Guanarito arenaviruses have emerged as causative agents of HF in Bolivia and Venezuela, respectively (22). Public health concerns about HF arenavirus infections are exacerbated by the lack of licensed vaccines and by the fact that current antiarenavirus therapies are limited to the use of the nucleoside analogue ribavirin, which is only partially effective and is associated with significant side effects. Therefore, it is important to develop novel drugs to combat human pathogenic arenaviruses.Similarly to many other enveloped NS RNA viruses, arenavirus infectious particles bud from the plasma membranes of infected cells. Evidence indicates that the M proteins of many enveloped NS RNA viruses play critical roles in virus budding (3). Accordingly, many of these M proteins are, in the absence of any other virus polypeptide, competent in budding and can form virus-like particles (VLPs). Budding of M proteins is often directed by L-domain motifs, which most frequently correspond to one of the following sequences: P(T/S)AP, PPXY, YXXL, or FPIV (3). Efficient M-mediated budding requires interactions between viral L domains and host factors, many of them involved in the cellular multivesicular body (MVB) sorting pathway (3). MVB formation requires the activity of a network of cytoplasmic protein complexes known as endosomal sorting complexes required for transport (ESCRT). Tsg101 is a component of the ESCRT-1 complex and plays a key role in the biogenesis of MVB. An AAA ATPase, Vps4, which is present in humans as two isoforms, Vps4A and Vps4B, binds to components of ESCRT-3 and mediates dissociation of ESCRT-3 complex from the endosomal membrane. We (20, 26) and others (24) have documented that Z is the driving force of arenavirus budding. As with many other bona fide viral budding proteins, all known arenavirus Z proteins contain P(T/S)AP, PPXY, or both, L-domain motifs that play a critical role in Z budding (20, 24). Tacaribe virus (TACV) Z protein, however, constitutes a unique exception, as it lacks both P(T/S)AP and PPXY L-domain motifs (Fig. ​(Fig.1A1A).Open in a separate windowFIG. 1.Arenavirus Z protein and its budding efficiency. (A) Schematic representation of Z proteins from LCMV, LASV, and TACV. G corresponds to the strictly conserved glycine residue found at position 2 of all known arenavirus Z proteins. The locations of bona fide PTAP (LASV), PPPY (LASV and LCMV), and YXXL (LASV and TACV) L-domain motifs are indicated, as well as that of the L-like domain motifs STAP (LCMV) and ASAP (TACV). (B) Budding activity of TACV Z protein. 293T cells were transfected with 0.25 μg of either pC-TACV-Z-HA or pC-LASV-Z-HA. At 36 h posttransfection, tissue culture supernatants were collected, and VLPs and total cell lysates were prepared as described previously (2). Levels of Z proteins in VLPs and cell lysates were determined by WB using an antibody to HA (sc-7392; Santa Cruz). The budding efficiency of LASV Z was set at 1.0. The data are averages and standard deviations from three independent experiments.     

两种常用数量性状连锁分析方法的原理和进展

在复杂性状疾病的家系连锁研究中,Haseman-Elston回归分析和方差组成模型是常用的两种数量性状连锁分析方法。前者主要针对同胞对的性状值差或和的平方进行回归分析;后者引用方差组成模型,将数量性状分解为遗传方差和环境方差,可估计二者对表型的影响。两种方法可应用于同胞对、核心家系或扩展家系,定位数量性状基因座。本文对这两种模型的原理、算法及其进展进行了综述,并给出了常用的统计软件包。 Abstract：In this article, we discussed two model-free methods for detecting genetic linkage for quantitative traits, Haseman-Elston regression approach and variance components approach. The former is a regression approach for detecting linkage based on the squared difference or squared sums in quantitative trait values of sib-pairs and their estimated marker IBD scores. The latter can jointly model covariate effects along with variance components, including genetic component and non-genetic sources of variability. We have outlined the model assumption, the algorithm and the extensions for the both methods.     

Exact Tests for Comparing Two Paired Proportions with Incomplete Data

Various asymptotic test procedures have been developed previously for testing the equality of two binomial proportions with partially incomplete paired data. Test procedures that discard incomplete observations have been shown to be less powerful than those procedures that utilize all available observations. On the other hand, asymptotic test procedures that utilize all available observations may not be reliable in small‐sample problems or sparse data structures. In this article, unconditional exact test procedures are proposed for testing the equality of two paired binomial proportions with partially incomplete paired data under a random mechanism. The proposed unconditional exact test methods are illustrated with real data from a neurological study. Empirical studies are conducted to investigate the performance of these and other test procedures with respect to size and power. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Evolution of the Cinnamyl/Sinapyl Alcohol Dehydrogenase (CAD/SAD) Gene Family: The Emergence of Real Lignin is Associated with the Origin of Bona Fide CAD

Lignin plays a vital role in plant adaptation to terrestrial environments. The cinnamyl alcohol dehydrogenase (CAD) catalyzes the last step in monolignol biosynthesis and might have contributed to the lignin diversity in plants. To investigate the evolutionary history and functional differentiation of the CAD gene family, we made a comprehensive evolutionary analysis of this gene family from 52 species, including bacteria, early eukaryotes and green plants. The phylogenetic analysis, together with gene structure and function, indicates that all members of land plants, except two of moss, could be divided into three classes. Members of Class I (bona fide CAD), generally accepted as the primary genes involved in the monolignol biosynthesis, are all from vascular plants, and form a robustly supported monophyletic group with the lycophyte CADs at the basal position. This class is also conserved in the predicted three-dimensional structure and the residues constituting the substrate-binding pocket of the proteins. Given that Selaginella has real lignin, the above evidence strongly suggests that the earliest occurrence of the bona fide CAD in the lycophyte could be directly correlated with the origin of lignin. Class II comprises members more similar to the aspen sinapyl alcohol dehydrogenase gene, and includes three groups corresponding to lycophyte, gymnosperm, and angiosperm. Class III is conserved in land plants. The three classes differ in patterns of evolution and expression, implying that functional divergence has occurred among them. Our study also supports the hypothesis of convergent evolution of lignin biosynthesis between red algae and vascular plants.     

Diabetes-Related Distress,Depression and Distress-Depression among Adults with Type 2 Diabetes Mellitus in Malaysia

Type 2 diabetes mellitus (T2DM) brings about an increasing psychosocial problem in adult patients. Prevalence data on and associated factors of diabetes related distress (DRD) and depression have been lacking in Asia. This study aimed to examine the prevalence of DRD and depression, and their associated factors in Asian adult T2DM patients. This study was conducted in three public health clinics measuring DRD (Diabetes Distress Scale, DDS), and depression (Patient Health Questionnaire, PHQ). Patients who were at least 30 years of age, had T2DM for more than one year, with regular follow-up and recent laboratory results (< 3 months) were consecutively recruited. Associations between DRD, depression and the combination DRD-depression with demographic and clinical characteristics were analysed using generalized linear models. From 752 invited people, 700 participated (mean age 56.9 years, 52.8% female, 52.9% Malay, 79.1% married). Prevalence of DRD and depression were 49.2% and 41.7%, respectively. Distress and depression were correlated, spearman’s r = 0.50. Patients with higher DRD were younger (OR 0.995, 95% CI 0.996 to 0.991), Chinese (OR 1.2, 95% CI 1.04 to 1.29), attending Dengkil health clinic (OR 1.1, 95% CI 1.00 to 1.22) and had higher scores on the PHQ (OR 1.1, 95% CI 1.04 to 1.06). Depression was less likely in the unmarried compared to divorced/separately living and those attending Dengkil health clinic, but more likely in patients with microvascular complications (OR 1.4, 95% CI 1.06 to 1.73) and higher DDS (OR 1.03, 95% CI 1.02 to 1.03). For the combination of DRD and depression, unemployment (OR 4.7, 95% CI 1.02 to 21.20) had positive association, whereas those under medical care at the Salak health clinics (OR 0.28, 95% CI 0.12 to 0.63), and those with a blood pressure > 130/80 mmHg (OR 0.53, 95% CI 0.32 to 0.89) were less likely to experience both DRD and depression. DRD and depression were common and correlated in Asian adults with T2DM at primary care level. Socio-demographic more than clinical characteristics were related to DRD and depression.     

Baseline Predictors of Success When Comparing Two Treatments

Since few medications are equally effective in all patients, physicians can maximize the risk/benefit ratio of therapy for their patients by limiting exposure based on baseline predictors of success. Traditional procedures typically evaluate the response of patients receiving the same treatment regimen without evaluating a comparator. However, when treatments are compared, such as in clinical trials, traditional procedures of identifying predictors must be modified to analyze the treatment effect on the primary outcome variable. We focus on clinical and statistical considerations that arise when developing baseline predictors through models which consider treatment differences. To illustrate an application of this method, we used data from 1,026 patients completing at least 6 months of double-blind therapy in clinical trials comparing fluoxetine (N=522) with placebo (N=504) for weight loss. Stepwise regression procedures were used to identify baseline variables which were predictive of a beneficial fluoxetine treatment effect on last-visit-carried-forward (LVCF) weight change. In this example, age, smoking activity, and uric acid concentration were the best baseline predictors of long-term treatment effect relative to LVCF weight change. Patients were more likely to achieve long-term benefit with fluoxetine if they were older, and/or were nonsmokers, and/or had high concentrations of uric acid at baseline. These predictors, developed through models keying on treatment effect, can be used to identify patients who are more likely to accrue benefits with active therapy beyond those expected with placebo therapy, thus enriching the treatment population so that a higher proportion of treated patients are successful.     

Two Approaches to an Archaeology of the Social

Social Theory in Archaeology. Michael Brian Schiffer. ed. Salt Lake City: University of Utah Press, 2000. 235 pp.
Social Transformations In Archaeology: Global and Local Perspectives. Kristian Kristiansen and Michael Row. lands. London: Routledge, 1998. 438 pp.     

Exome Sequencing from Nanogram Amounts of Starting DNA: Comparing Three Approaches

Hybridization-based target enrichment protocols require relatively large starting amounts of genomic DNA, which is not always available. Here, we tested three approaches to pre-capture library preparation starting from 10 ng of genomic DNA: (i and ii) whole-genome amplification of DNA samples with REPLI-g (Qiagen) and GenomePlex (Sigma) kits followed by standard library preparation, and (iii) library construction with a low input oriented ThruPLEX kit (Rubicon Genomics). Exome capture with Agilent SureSelect^XT2 Human AllExon v4+UTRs capture probes, and HiSeq2000 sequencing were performed for test libraries along with the control library prepared from 1 µg of starting DNA. Tested protocols were characterized in terms of mapping efficiency, enrichment ratio, coverage of the target region, and reliability of SNP genotyping. REPLI-g- and ThruPLEX-FD-based protocols seem to be adequate solutions for exome sequencing of low input samples.     

Depression among Asian-American Adults in the Community: Systematic Review and Meta-Analysis

Objectives

In this systematic review, we provide an overview of the literature on depression among Asian-Americans and explore the possible variations in depression prevalence estimates by methodological and demographic factors.

Methods

Six databases were used to identify studies reporting a prevalence estimate for depression in Asian-American adults in non-clinical settings. Meta-analysis was used to calculate pooled estimates of rates of depression by assessment type. Statistical heterogeneity was assessed for subgroup analyses by gender, age, ethnicity, and other participant characteristics.

Results

A total of 58 studies met the review criteria (n = 21.731 Asian-American adults). Heterogeneity across the studies was considerably high. The prevalence of major depression assessed via standardized clinical interviews ranged between 4.5% and 11.3%. Meta-analyses revealed comparable estimated prevalence rates of depression as measured by the Center for Epidemiologic Studies Depression Scale (35.6%, 95% CI 27.6%–43.7%) and the Geriatric Depression Scale (33.1%, 95% CI 14.9%–51.3%). Estimates varied by Asian racial/ethnic group and other participant characteristics. Estimates of depression among special populations, which included maternity, caregivers, and homosexuals, were significantly higher than estimates obtained from other samples (58.8% vs 29.3%, p = .003). Estimates of depression among Korean and Filipino-Americans were similar (33.3%-34.4%); however, the estimates were twice as high as those for Chinese-Americans (15.7%; p = .012 for Korean, p = .049 for Filipino).

Conclusion

There appears to be wide variability in the prevalence rates of depression among Asian-Americans in the US. Practitioners and researchers who serve Asian-American adults need to be sensitive to the potential diversity of the expression of depression and treatment-seeking across Asian-American subgroups. Public health policies to increase Asian-American access to mental health care, including increased screening, are necessary. Further work is needed to determine whether strategies to reduce depression among specific Asian racial/ethnic groups is warranted.     

Survival of Patients with Primary Brain Tumors: Comparison of Two Statistical Approaches

Purpose

We reviewed the survival time for patients with primary brain tumors undergoing treatment with stereotactic radiation methods at the Masaryk Memorial Cancer Institute Brno. We also identified risk factors and characteristics, and described their influence on survival time.

Methods

In summarizing survival data, there are two functions of principal interest, namely, the survival function and the hazard function. In practice, both of them can depend on some characteristics. We focused on nonparametric methods, propose a method based on kernel smoothing, and compared our estimates with the results of the Cox regression model. The hazard function is conditional to age and gross tumor volume and visualized as a color-coded surface. A multivariate Cox model was also designed.

Results

There were 88 patients with primary brain cancer, treated with stereotactic radiation. The median survival of our patient cohort was 47.8 months. The estimate of the hazard function has two peaks (about 10 months and about 40 months). The survival time of patients was significantly different for various diagnoses (p≪0.001), KI (p = 0.047) and stereotactic methods (p = 0.033). Patients with a greater GTV had higher risk of death. The suitable threshold for GTV is 20 cm³. Younger patients with a survival time of about 50 months had a higher risk of death. In the multivariate Cox regression model, the selected variables were age, GTV, sex, diagnosis, KI, location, and some of their interactions.

Conclusion

Kernel methods give us the possibility to evaluate continuous risk variables and based on the results offer risk-prone patients a different treatment, and can be useful for verifying assumptions of the Cox model or for finding thresholds of continuous variables.