Concerted action of ataxin-2 and PABPC1-bound mRNA poly(A) tail in the formation of stress granules.

Stress induces global stabilization of the mRNA poly(A) tail (PAT) and the assembly of untranslated poly(A)-tailed mRNA into mRNPs that accumulate in stress granules (SGs). While the mechanism behind stress-induced global PAT stabilization has recently emerged, the biological significance of PAT stabilization under stress remains elusive. Here, we demonstrate that stress-induced PAT stabilization is a prerequisite for SG formation. Perturbations in PAT length impact SG formation; PAT shortening, achieved by overexpressing mRNA deadenylases, inhibits SG formation, whereas PAT lengthening, achieved by overexpressing their dominant negative mutants or downregulating deadenylases, promotes it. PABPC1, which specifically binds to the PAT, is crucial for SG formation. Complementation analyses reveal that the PABC/MLLE domain of PABPC1, responsible for binding PAM2 motif-containing proteins, plays a key role. Among them, ataxin-2 is a known SG component. A dominant-negative approach reveals that the PAM2 motif of ataxin-2 is essential for SG formation. Notably, ataxin-2 increases stress sensitivity, lowering the threshold for SG formation, probably by promoting the aggregation of PABPC1-bound mRNA. The C-terminal region is responsible for the self-aggregation of ataxin-2. These findings underscore the critical roles of mRNA PAT, PABPC1 and ataxin-2 in SG formation and provide mechanistic insights into this process.

Fission yeast Ccq1 is a modulator of telomerase activity.

Shelterin, the telomeric protein complex, plays a crucial role in telomere homeostasis. In fission yeast, telomerase is recruited to chromosome ends by the shelterin component Tpz1 and its binding partner Ccq1, where telomerase binds to the 3' overhang to add telomeric repeats. Recruitment is initiated by the interaction of Ccq1 with the telomerase subunit Est1. However, how telomerase is released following elongation remains to be established. Here, we show that Ccq1 also has a role in the suppression of telomere elongation, when coupled with the Clr4 histone H3 methyl-transferase complex and the Clr3 histone deacetylase and nucleosome remodelling complex, SHREC. We have dissected the functions of Ccq1 by establishing a Ccq1-Est1 fusion system, which bypasses the telomerase recruitment step. We demonstrate that Ccq1 forms two distinct complexes for positive and negative telomerase regulation, with Est1 and Clr3 respectively. The negative form of Ccq1 promotes dissociation of Ccq1-telomerase from Tpz1, thereby restricting local telomerase activity. The Clr4 complex also has a negative regulation activity with Ccq1, independently of SHREC. Thus, we propose a model in which Ccq1-Est1 recruits telomerase to mediate telomere extension, whilst elongated telomeric DNA recruits Ccq1 with the chromatin-remodelling complexes, which in turn releases telomerase from the telomere.

How long does telomerase extend telomeres? Regulation of telomerase release and telomere length homeostasis.

Telomerase, the enzyme that replenishes telomeres, is essential for most eukaryotes to maintain their generations. Telomere length homeostasis is achieved via a balance between telomere lengthening by telomerase, and erosion over successive cell divisions. Impaired telomerase regulation leads to shortened telomeres and can cause defects in tissue maintenance. Telomeric DNA is composed of a repetitive sequence, which recruits the protective protein complex, shelterin. Shelterin, together with chromatin remodelling proteins, shapes the heterochromatic structure at the telomere and protects chromosome ends. Shelterin also provides a foothold for telomerase to be recruited and facilitates telomere extension. Such mechanisms of telomere recruitment and activation are conserved from unicellular eukaryotes to humans, with the rate of telomere extension playing an important role in determining the length maintained. Telomerase can be processive, adding multiple telomeric repeats before dissociating. However, a question remains: how does telomerase determine the number of repeats to add? In this review, I will discuss about how telomerase can monitor telomere extension using fission yeast as a model. I propose a model whereby the accumulation of the Pot1 complex on the synthesised telomere single-strand counteracts retention of telomerase via chromatin proteins and the similar system may be conserved in mammals.

Use of the HPRT gene to study nuclease-induced DNA double-strand break repair.

Understanding the mechanisms of chromosomal double-strand break repair (DSBR) provides insight into genome instability, oncogenesis and genome engineering, including disease gene correction. Research into DSBR exploits rare-cutting endonucleases to cleave exogenous reporter constructs integrated into the genome. Multiple reporter constructs have been developed to detect various DSBR pathways. Here, using a single endogenous reporter gene, the X-chromosomal disease gene encoding hypoxanthine phosphoribosyltransferase (HPRT), we monitor the relative utilization of three DSBR pathways following cleavage by I-SceI or CRISPR/Cas9 nucleases. For I-SceI, our estimated frequencies of accurate or mutagenic non-homologous end-joining and gene correction by homologous recombination are 4.1, 1.5 and 0.16%, respectively. Unexpectedly, I-SceI and Cas9 induced markedly different DSBR profiles. Also, using an I-SceI-sensitive HPRT minigene, we show that gene correction is more efficient when using long double-stranded DNA than single- or double-stranded oligonucleotides. Finally, using both endogenous HPRT and exogenous reporters, we validate novel cell cycle phase-specific I-SceI derivatives for investigating cell cycle variations in DSBR. The results obtained using these novel approaches provide new insights into template design for gene correction and the relationships between multiple DSBR pathways at a single endogenous disease gene.

Association between the body mass index and the clinical findings in patients with acute heart failure: evaluation of the obesity paradox in patients with severely decompensated acute heart failure.

Obesity is known to be associated with the development of heart failure (HF). However, the relationship between the body mass index (BMI) and acute HF (AHF) remains to be elucidated. Eight hundred and eight AHF patients were enrolled in this study. The patients were assigned to four groups according to their BMI values: severely thin (n = 11, BMI <16), normal/underweight (n = 579, 16 ≤ BMI <25), overweight (n = 178, 25 ≤ BMI <30) and obese (n = 40, BMI ≥30). The patients in the severely thin group were more likely to be female, have systolic blood pressure (SBP) <100 mmHg and have valvular disease than normal/underweight patients. The patients in the overweight group were significantly younger than those in the normal/underweight, and those in the overweight group were more likely to have SBP ≥140 mmHg and hypertensive heart disease and less likely to have valvular disease than the patients in the normal/underweight group. The prognosis, including all-cause death, was significantly poorer among patients who were severely thin than those who were normal/underweight, overweight and significantly better among those who were overweight than those who were normal/underweight, severely thin and obese patients. A multivariate Cox regression model identified that severely thin [HR: 3.372, 95% confidence interval (CI) 1.362-8.351] and overweight (HR: 0.615, 95% CI 0.391-0.966) were independent predictors of 910-day mortality as the reference of normal/underweight. Overweight patients tended to have SBP ≥140 mmHg and be relatively young, while severely thin patients tended to have SBP <100 mmHg and be female. These factors were associated with a better prognosis of overweight patients and adverse outcomes in severely thin patients. These factors may contribute to the "obesity paradox" in severely decompensated AHF patients.

Sequential and counter-selectable cassettes for fission yeast.

BACKGROUND: Fission yeast is one of the most commonly used model organisms for studying genetics. For selection of desirable genotypes, antibiotic resistance cassettes are widely integrated into the genome near genes of interest. In yeasts, this is achieved by PCR amplification of the cassette flanked by short homology sequences, which can be incorporated by homology directed repair. However, the currently available cassettes all share the same tef promoter and terminator sequences. It can therefore be challenging to perform multiple genetic modifications by PCR-based targeting, as existing resistance cassettes in strains can be favored for recombination due to shared homology between the cassettes. RESULTS: Here we have generated new selection cassettes that do not recombine with those traditionally used. We achieved this by swapping the tef promoter and terminator sequences in the established antibiotic resistance MX6 cassette series for alternative promoters and/or terminators. The newly created selection cassettes did not recombine with the tef-containing MX6 cassettes already present in the genome, allowing for sequential gene targeting using the PCR-based method. In addition, we have generated a series of plasmids to facilitate the C-terminal tagging of genes with desired epitopes. We also utilized the anti-selection gene HSV-TK, which results in cell death in strains grown on the drug 5-Fluoro-2'-deoxyuridine (FdU, Floxuridin or FUDR). By fusing an antibiotic resistance gene to HSV-TK, we were able to select on the relevant antibiotic as well as counter-select on FdU media to confirm the desired genomic modification had been made. We noted that the efficiency of the counter selection by FdU was enhanced by treatment with hydroxyurea. However, a number of DNA replication checkpoint and homologous recombination mutants, including rad3∆, cds1∆, rad54∆ and rad55∆, exhibited sensitivity to FdU even though those strains did not carry the HSV-TK gene. To remove counter-selectable markers, we introduced the Cre-loxP irreversible recombination method. Finally, utilizing the negative selectable markers, we showed efficient induction of point mutations in an endogenous gene by a two-step transformation method. CONCLUSIONS: The plasmid constructs and techniques described here are invaluable tools for sequential gene targeting and will simplify construction of fission yeast strains required for study.

The serum heart-type fatty acid-binding protein (HFABP) levels can be used to detect the presence of acute kidney injury on admission in patients admitted to the non-surgical intensive care unit.

BACKGROUND: No cardiac biomarkers for detecting acute kidney injury (AKI) on admission in non-surgical intensive care patients have been reported. The aim of the present study is to elucidate the role of cardiac biomarkers for quickly identifying the presence of AKI on admission. METHODS: Data for 1183 patients who underwent the measurement of cardiac biomarkers, including the serum heart-type fatty acid-binding protein (s-HFABP) level, in the emergency department were screened, and 494 non-surgical intensive care patients were enrolled in this study. Based on the RIFLE classification, which was the ratio of the serum creatinine value recorded on admission to the baseline creatinine value, the patients were assigned to a no-AKI (n = 349) or AKI (Class R [n = 83], Class I [n = 36] and Class F [n = 26]) group on admission. We evaluated the diagnostic value of the s-H-FABP level for detecting AKI and Class I/F. The mid-term prognosis, as all-cause death within 180 days, was also evaluated. RESULTS: The s-H-FABP levels were significantly higher in the Class F (79.2 [29.9 to 200.3] ng/mL) than in the Class I (41.5 [16.7 to 71.6] ng/mL), the Class R (21.1 [10.2 to 47.9] ng/mL), and no-AKI patients (8.8 [5.4 to 17.7] ng/mL). The most predictive values for detecting AKI were Q2 (odds ratio [OR]: 3.743; 95 % confidence interval [CI]: 1.693-8.274), Q3 (OR: 9.427; 95 % CI: 4.124-21.548), and Q4 (OR: 28.000; 95 % CI: 11.245-69.720), while those for Class I/F were Q3 (OR: 5.155; 95 % CI: 1.030-25.790) and Q4 (OR: 22.978; 95 % CI: 4.814-109.668). The s-HFABP level demonstrating an optimal balance between sensitivity and specificity (70.3 and 72.8 %, respectively; area under the curve: 0.774; 95 % CI: 0.728-0.819) was 15.7 ng/mL for AKI and 20.7 ng/mL for Class I/F (71.0 and 83.1 %, respectively; area under the curve: 0.818; 95 % CI: 0.763-0.873). The prognosis was significantly poorer in the high serum HFABP with AKI group than in the other groups. CONCLUSIONS: The s-H-FABP level is an effective biomarker for detecting AKI in non-surgical intensive care patients.

Telomere protein Rap1 is a charge resistant scaffolding protein in chromosomal bouquet formation.

BACKGROUND: Chromosomes reorganize in early meiotic prophase to form the so-called telomere bouquet. In fission yeast, telomeres localize to the nuclear periphery via interaction of the telomeric protein Rap1 with the membrane protein Bqt4. During meiotic prophase, the meiotic proteins Bqt1-2 bind Rap1 and tether to the spindle pole body to form the bouquet. Although it is known that this polarized chromosomal arrangement plays a crucial role in meiotic progression, the molecular mechanisms of telomere bouquet regulation are poorly understood. RESULTS: Here, we detected high levels of Rap1 phospho-modification throughout meiotic prophase, and identified a maximum of 35 phosphorylation sites. Concomitant phosphomimetic mutation of the modification sites suggests that Rap1 hyper-phosphorylation does not directly regulate telomere bouquet formation or dissociation. Despite the negative charge conferred by its highly phosphorylated state, Rap1 maintains interactions with its binding partners. Interestingly, mutations that change the charge of negatively charged residues within the Bqt1-2 binding site of Rap1 abolished the affinity to the Bqt1-2 complex, suggesting that the intrinsic negative charge of Rap1 is crucial for telomere bouquet formation. CONCLUSIONS: Whereas Rap1 hyper-phosphorylation observed in meiotic prophase does not have an apparent role in bouquet formation, the intrinsic negative charge of Rap1 is important for forming interactions with its binding partners. Thus, Rap1 is able to retain bouquet formation under heavily phosphorylated status.

Chemical genetic analyses of quantitative changes in Cdk1 activity during the human cell cycle.

Cyclin-dependent kinase 1 (Cdk1) controls cell proliferation and is inhibited by promising anticancer agents, but its mode of action and the consequences of its inhibition are incompletely understood. Cdk1 promotes S- and M-phases during the cell-cycle but also suppresses endoreduplication, which is associated with polyploidy and genome instability. The complexity of Cdk1 regulation has made it difficult to determine whether these different roles require different thresholds of kinase activity and whether the surge of activity as inhibitory phosphates are removed at mitotic onset is essential for cell proliferation. Here, we have used chemical genetics in a human cell line to address these issues. We rescued cells lethally depleted of endogenous Cdk1 with an exogenous Cdk1 conferring sensitivity to one ATP analogue inhibitor (1NMPP1) and resistance to another (RO3306). At no 1NMPP1 concentration was mitosis in rescued clones prevented without also inducing endoreduplication, suggesting that these two key roles for Cdk1 are not simply controlled by different Cdk1 activity thresholds. We also rescued RO3306-resistant clones using exogenous Cdk1 without inhibitory phosphorylation sites, indicating that the mitotic surge of Cdk1 activity is dispensable for cell proliferation. These results suggest that the basic mammalian cycle requires at least some qualitative changes in Cdk1 activity and that quantitative increases in activity need not be rapid. Furthermore, the viability of cells that are unable to undergo rapid Cdk1 activation, and the strong association between endoreduplication and impaired proliferation, may place restrictions on the therapeutic use of a Cdk1 inhibitors.

A single internal telomere tract ensures meiotic spindle formation.

Contact between telomeres and the fission yeast spindle pole body during meiotic prophase is crucial for subsequent spindle assembly, but the feature of telomeres that confers their ability to promote spindle formation remains mysterious. Here we show that while strains harbouring circular chromosomes devoid of telomere repeat tracts undergo aberrant meiosis with defective spindles, the insertion of a single internal telomere repeat stretch rescues the spindle defects. Moreover, the telomeric overhang-binding protein Pot1 is dispensable for rescue of spindle formation. Hence, an inherent feature of the double-strand telomeric region endows telomeres with the capacity to promote spindle formation.

Serum heart-type fatty acid-binding protein level can be used to detect acute kidney injury on admission and predict an adverse outcome in patients with acute heart failure.

BACKGROUND: Different mechanisms of acute kidney injury (AKI) may exist for acute heart failure (AHF) patients compared with other patients. METHODS AND RESULTS: We analyzed data from 282 patients with AHF. The biomarkers were measured within 30 min of admission. Patients were assigned to a no-AKI (n=213) or AKI group (Class R (n=49), Class I (n=15) or Class F (n=5)) using the RIFLE classifications on admission. We evaluated the relationships between the biomarkers and AKI, in-hospital mortality, all-cause death and HF events (HF re-admission, all-cause death) within 90 days. The serum heart-type fatty acid-binding protein (s-HFABP) levels were significantly higher in the AKI than in the no-AKI group, and the predictive biomarker for AKI was s-HFABP (odds ratio: 6.709; 95% confidence interval: 3.362-13.391). s-HFABP demonstrated an optimal balance between sensitivity and specificity (71.0%, 79.3%; area under the receiver-operating characteristic curve [AUC]=0.790) at 22.8 ng/ml for AKI, at 22.8 ng/ml for Class I/F (90.0%, 71.4%; AUC=0.836) and at 21.0 ng/ml for in-hospital mortality (74.3%, 70.0%; AUC=0.726). The Kaplan-Meier survival curves showed a significantly poorer prognosis in the high s-HFABP group (≥22.9 ng/ml) than in other groups. CONCLUSIONS: The s-HFABP level can indicate AKI on admission, and a high s-HFABP level is associated with a poorer prognosis for AHF patients.

Seasonal variation in patients with acute heart failure: prognostic impact of admission in the summer.

There have been few reports discussing the clinical significance of the season of admission of acute heart failure (AHF) patients. The data of 661 patients with AHF admitted to the intensive care unit were analyzed. Patients were assigned to a summer admission (Group-S, n = 113, between July and September), a winter admission (Group-W, n = 214, between December and February), or to the other seasons admission group (Group-O, n = 334). We evaluated the relationships between the seasonal variations and the clinical profiles, and the long-term prognosis. There were significantly more patients with cardiomyopathy and New York Heart Association class 4, and the serum levels of total bilirubin were significantly higher in Group-S (85.8, 24.8 %, and 0.60 [0.50-0.90]) than in Group-W (75.2, 15.4 %, and 0.60 [0.40-0.78]). The left ventricular ejection fraction on admission was significantly reduced and intravenous administration of dobutamine was used more frequently in Group-S (30.0 [25.0-46.0], 31.9 %) than in Group-W (34.4 [25.2-48.0], 20.6 %) and Group-O (35.0 [25.0-46.0], 19.8 %). The multivariate Cox regression model found that summer admission was independently associated with cardiovascular death (HR: 1.58, 95 % CI 1.01-2.48; p = 0.044) and heart failure (HF) events (HR: 1.55, 95 % CI 1.05-2.28; p = 0.028). The Kaplan-Meier curves showed that the cardiovascular death rate was significantly higher in Group-S than in Group-W and Group-O, and the HF events were significantly higher in Group-S than in Group-O. The summer admission AHF patients included sicker patients, and the prognosis in these patients was worse than in the patients admitted at other times.

Immediate administration of tolvaptan prevents the exacerbation of acute kidney injury and improves the mid-term prognosis of patients with severely decompensated acute heart failure.

BACKGROUND: Tolvaptan, an oral selective vasopressin 2 receptor antagonist that acts on the distal nephrons to cause a loss of electrolyte-free water, is rarely used during the acute phase of acute heart failure (AHF). METHODS AND RESULTS: We investigated 183 AHF patients admitted to the intensive care unit and administered tolvaptan (7.5mg) with continuous intravenous furosemide, and then additionally at 12-h intervals until HF was compensated. When intravenous furosemide was changed to peroral use, the administration of tolvaptan was stopped. The patients were assigned to tolvaptan (n=52) or conventional treatment (n=131) groups. The amount of intravenous furosemide was significantly lower (35.4 [16.3-56.0] mg vs. 80.0 [30.4-220.0] mg), the urine volume was significantly higher on days 1 and 2 (3,691 [3,109-4,198] ml and 2,953 [2,128-3,592] ml vs. 2,270 [1,535-3,258] ml and 2,129 [1,407-2,906] ml) and the numbers of patients with worsening-AKI (step-up RIFLE Class to I or F) and Class F were significantly fewer (5.8% and 1.9% vs. 19.1% and 16.0%) in the tolvaptan group than in the conventional group, respectively. One of the specific medications indicated worsening-AKI and in-hospital mortality was tolvaptan (odds ratio [OR] 0.155, 95% confidence interval [CI] 0.037-0.657 and OR 0.191, 95% CI 0.037-0.985). The Kaplan-Meier curves showed that the death rate within 6 months was significantly lower in the tolvaptan group. The same result was found after propensity matching of the data. CONCLUSIONS: Early administration of tolvaptan could prevent exacerbation of AKI and improve the prognosis for AHF patients.

Prognostic impact of acute kidney injury in patients with acute decompensated heart failure.

BACKGROUND: The relationship between acute kidney injury (AKI) in the acute phase of acute decompensated heart failure (ADHF) and patient outcome has not yet been reported. METHODS AND RESULTS: Data for 625 patients with ADHF admitted to the intensive care unit were analyzed. No AKI occurred in 281 patients (no AKI) during the first 5 days. The AKI patients were assigned to 3 groups based on the timing: AKI present on admission and stable risk, injury, failure, loss, and endstage (RIFLE) class (stable early AKI; n=125), stepped-up RIFLE class (worsening early AKI; n=49), or AKI that occurred after admission (late AKI; n=170). The AKI patients were grouped into another 3 groups based on severity: class R (risk; n=214), class I (injury; n=73), or class F (failure; n=57). A multivariate logistic regression model found class I, class F, late AKI and worsening early AKI to be independently associated with in-hospital mortality. Kaplan-Meier survival curves showed that the survival rate in any-cause death during 2 years was significantly lower in class I, class F and the worsening early-AKI group, and there were significantly more HF events in class F and the worsening early-AKI group. There were significantly more class I and class F patients in the worsening early-AKI group. CONCLUSIONS: The presence of AKI on admission, worsening of AKI, and severe AKI (class I or class F) are associated with a poorer prognosis for ADHF patients.

Characteristics of patients with cardiac arrest caused by coronary vasospasm.

BACKGROUND: Although coronary vasospasm (CVS) would be one of the major causes of out-of-hospital cardiac arrest (OHCA), the characteristics of patients with cardiac arrest caused by CVS have not been clarified. METHODS AND RESULTS: In study 1, 1,000 consecutive patients with OHCA were retrospectively categorized based on the cause of OHCA, and the prevalence of CVS OHCA was elucidated. In study 2, 138 consecutive CVS patients were divided into 2 groups: CVS with cardiac arrest (arrest-CVS, n=12) and CVS without cardiac arrest (non-arrest-CVS, n=126). In study 1, 589 patients had OHCA caused by cardiovascular disease and 121 patients were successfully resuscitated. Among the 121 resuscitated patients, 9 had CVS OHCA. In study 2, the incidence of cardiac events (ie, cardiac arrest or chest pain) occurring on vigorous exertion, in the daytime and without prodromal chest symptoms was higher in the arrest-CVS group than in the non-arrest-CVS group. CONCLUSIONS: CVS is an important cause of OHCA. Because significantly different characteristics are observed between CVS patients with cardiac arrest and those without, care should be taken to diagnose CVS as the cause of cardiac arrest.

Predictive score for survival after percutaneous cardiopulmonary support in cardiovascular disease patients- evaluation of pre-procedural information.

BACKGROUND: The predictive factors for survival after percutaneous cardiopulmonary support (PCPS) are unknown. METHODS AND RESULTS: Data for 105 patients with cardiovascular disease requiring PCPS were analyzed. The patients were divided into a survivor (n=21) or a non-survivor group (n=84). The age was significantly lower, and there were more patients with fulminant myocarditis and PCPS attempted before cardiac arrest (CA) in the survivor group. Additionally, there were fewer cases of out-of-hospital CA, and the mean time from CA to PCPS was shorter in the survivor group. On multivariate logistic regression it was found that the age and the time from CA to PCPS were independently associated with survival. A predictive scoring system was constructed that included the following: (1) age <50 years; (2) diagnosis of fulminant myocarditis; (3) no out-of-hospital CA; (4) PCPS attempted before CA; and (5) time from CA to PCPS <45 min. The predictive score was significantly higher in the survivor than in the non-survivor group (2.33 ± 1.32 vs. 1.06 ± 1.02). The sensitivity and specificity for survival were 85.7% and 66.7% when the score was ≥ 2. Kaplan-Meier survival analysis showed that any-cause death was significantly higher in patients with PCPS survival score ≤ 1 than in those with a score ≥ 2. CONCLUSIONS: PCPS survival score is suitable for clinically predicting survival in patients with cardiovascular disease undergoing PCPS.

Age-related telomere attrition in the human putamen.

Age is a major risk factor for neurodegenerative diseases. Shortening of leucocyte telomeres with advancing age, arguably a measure of "biological" age, is a known phenomenon and epidemiologically correlated with age-related disease. The main mechanism of telomere shortening is cell division, rendering telomere length in post-mitotic cells presumably stable. Longitudinal measurement of human brain telomere length is not feasible, and cross-sectional cortical brain samples so far indicated no attrition with age. Hence, age-related changes in telomere length in the brain and the association between telomere length and neurodegenerative diseases remain unknown. Here, we demonstrate that mean telomere length in the putamen, a part of the basal ganglia, physiologically shortens with age, like leukocyte telomeres. This was achieved by using matched brain and leukocyte-rich spleen samples from 98 post-mortem healthy human donors. Using spleen telomeres as a reference, we further found that mean telomere length was brain region-specific, as telomeres in the putamen were significantly shorter than in the cerebellum. Expression analyses of genes involved in telomere length regulation and oxidative phosphorylation revealed that both region- and age-dependent expression pattern corresponded with region-dependent telomere length dynamics. Collectively, our results indicate that mean telomere length in the human putamen physiologically shortens with advancing age and that both local and temporal gene expression dynamics correlate with this, pointing at a potential mechanism for the selective, age-related vulnerability of the nigro-striatal network.

Long-term prognostic impact after acute kidney injury in patients with acute heart failure.

The relationship between the short-term prognosis of acute heart failure (AHF) and acute kidney injury (AKI) using the risk, injury, failure, and end stage (RIFLE) criteria has already been reported, however, the relationship between the long-term prognosis and AKI has not. We investigated the relationship between the long-term prognosis after discharge and AKI using the RIFLE criteria. Five hundred patients with AHF admitted to our intensive care unit were analyzed. Patients were assigned to a no AKI (n = 156), Class R (risk; n = 201), Class I (injury; n = 73), or Class F (failure; n = 70) using the most severe RIFLE classifications during hospitalization. We evaluated the relationships between the RIFLE classifications and any-cause death, and HF events including death and readmission for HF within 1 year. A multivariate logistic regression model found that Class I (P = 0.013, OR: 2.768; 95% CI: 1.236-6.199) and Class F (P < 0.001, OR: 7.920; 95% CI: 3.497-17.938) were independently associated with any-cause death, and Class F was associated with HF events (P = 0.001, OR: 3.486; 95% CI: 1.669-7.281). The Kaplan-Meier survival curves showed the prognosis, including death, to be significantly poorer in Class I than in no AKI and Class R, to be significantly poorer in Class F than in no AKI, Class R, and Class I, and the prognosis including HF events to be significantly poorer in Class F than in no AKI, Class R, and Class I. The presence of severe AKI (Class I and F) was independently associated with long-term mortality for AHF.

Soluble lectin-like oxidized low-density lipoprotein receptor-1 as an early biomarker for ST elevation myocardial infarction: time-dependent comparison with other biomarkers: time-dependent comparison with other biomarkers.

BACKGROUND: The diagnostic sensitivity of myocardial necrosis markers, such as creatine kinase-MB (CK-MB), cardiac troponins, myoglobin and heart-type fatty acid-binding protein (H-FABP) for the earliest stage of ST-elevation myocardial infarction (STEMI), remains insufficient. We compared a new biomarker of plaque vulnerability (soluble lectin-like oxidized low-density lipoprotein receptor-1, sLOX-1) with other biomarkers at the earliest stage of STEMI. METHODS AND RESULTS: Plasma sLOX-1 levels were measured in 125 STEMI, 44 non-STEMI (NSTEMI) and 125 non-acute myocardial infarction (non-AMI) patients and were significantly (P < 0.0001) higher in the STEMI and NSTEMI than in the non-AMI patients (median, 25th and 75th percentiles: 241.0, 132.3 and 472.2 vs. 147.3, 92.9 and 262.4 vs. 64.3, 54.4 and 84.3 pg/ml, respectively). At the optimal cut-off value of 91.0 pg/ml, sLOX-1 discriminated STEMI from non-AMI with 89.6% sensitivity and 82.4% specificity. Time-dependent changes in sLOX-1, H-FABP, myoglobin, troponin T and CK-MB were analyzed in 27 STEMI patients. Elevated plasma sLOX-1 levels persisted for 24h after admission, whereas other markers were not elevated at the time of admission and peaked at ≥ 2h thereafter. The diagnostic sensitivity of sLOX-1, H-FABP, myoglobin, troponin T and CK-MB for STEMI upon admission (89 min after onset) was 93%, 78%, 70%, 56% and 33%, respectively. CONCLUSIONS: Plasma sLOX-1 diagnosed the early stages of STEMI more accurately than H-FABP, myoglobin, troponin T and CK-MB.