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Background: Although acetylsalicylic acid is the most commonly used antithrombotic agent for the secondary prevention of cardiovascular events, residual atherothrombotic risk has prompted a guideline recommendation for the addition of dual antiplatelet therapy (DAPT) or dual pathway inhibition (DPI) in high vascular risk patients. Accordingly, the CONNECT CVD quality enhancement initiative provides a contemporary "snapshot" of the clinical features and antithrombotic management of atherosclerotic cardiovascular disease (ASCVD) patients in Canada., Methods: Canadian cardiologists (49 cardiologists from six provinces) undertook a retrospective chart audit of 10 ASCVD patients in their outpatient practice who met the Cardiovascular Outcomes for People Using Anticoagulation Strategy-like criteria from May 2018 to April 2019., Results: Of the 492 (two cardiologists provided 11 patients) enroled, average age was 70 years, 25% were female, 39% had diabetes and 20% had atrial fibrillation. Prior revascularisation was common (percutaneous coronary artery intervention 61%, coronary artery bypass graft 39%), with 31% having multivessel disease. A total of 47% of patients had a Reduction of Atherothrombosis for Continued Health bleeding score of ≥11 (~2.8% risk of serious bleeding at 2 years). Single antiplatelet therapy (SAPT) alone was most commonly used (62%), while 22% were on DAPT alone. In total, 22% were on oral anticoagulation (OAC), with 16% being on non-vitamin K oral anticoagulant alone, 5% on DPI and 1% received triple therapy., Conclusions: In contemporary Canadian clinical practice of stable ASCVD patients, a large number of patients receive antithrombotic therapy other than SAPT. Further efforts are required to guide the appropriate selection of patients in whom more potent antithrombotic therapies may safely reduce residual risk., (© 2021 John Wiley & Sons Ltd.)

Aliskiren is the first direct renin inhibitor approved for the treatment of hypertension. Blood pressure (BP) control in stage 2 hypertension with aliskiren monotherapy has not been reported. This was a post hoc analysis of the subgroup of patients with stage 2 systolic hypertension (baseline mean sitting systolic BP [msSBP]≥160 mmHg) who completed the 12-week monotherapy phase of a 6-month, double-blind, randomized study. A total of 175 patients were randomized to aliskiren 150 mg (n = 88) or ramipril 5 mg (n = 87) with optional up-titration to aliskiren 300 mg or ramipril 10 mg, respectively, at weeks 6 and 12. In the subgroup of patients with stage 2 systolic hypertension, aliskiren lowered msSBP and mean sitting diastolic BP (msDBP) by 22.3/12.7 mmHg from baseline to week 12; compared with a reduction of 18.1/10.2 mmHg with ramipril. The maximum BP reductions achieved with aliskiren were 60.0/34.0 mmHg (from a baseline of 172.7/107.3 mmHg). Aliskiren was noninferior (P < 0.0001) to ramipril for SBP reduction with nonsignificant superiority (P = 0.052), and superior (P = 0.043) to ramipril for DBP reduction. The proportion of patients who achieved BP control (<140/90 mmHg) after 12 weeks of monotherapy was larger with aliskiren (34/88, 38.6%) than with ramipril (22/87, 25.3%; P = 0.038). In this post hoc analysis, 12 weeks of monotherapy with aliskiren 150-300 mg provided effective mean BP reductions (22/13 mmHg) and was superior to ramipril 5-10 mg in controlling BP in patients with stage 2 systolic hypertension., (© 2010 Blackwell Publishing Ltd.)

Targeted deletion of IA-2 and IA-2beta, major autoantigens in type 1 diabetes and transmembrane secretory vesicle proteins, results in impaired secretion of hormones and neurotransmitters. In the present study, we evaluated the effect of these deletions on daily rhythms in blood pressure, heart rate, core body temperature, and spontaneous physical and neuronal activity. We found that deletion of both IA-2 and IA-2beta profoundly disrupts the usual diurnal variation of each of these parameters, whereas the deletion of either IA-2 or IA-2beta alone did not produce a major change. In situ hybridization revealed that IA-2 and IA-2beta transcripts are highly but nonrhythmically expressed in the suprachiasmatic nuclei, the site of the brain's master circadian oscillator. Electrophysiological studies on tissue slices from the suprachiasmatic nuclei showed that disruption of both IA-2 and IA-2beta results in significant alterations in neuronal firing. From these studies, we concluded that deletion of IA-2 and IA-2beta, structural proteins of secretory vesicles and modulators of neuroendocrine secretion, has a profound effect on the circadian system.

Introduction: This subgroup analysis assessed the effects of treatment based on the direct renin inhibitor, aliskiren, or the angiotensin-converting enzyme inhibitor, ramipril, on plasma renin activity (PRA), plasma renin concentration (PRC) and other biomarkers in a 26-week randomised, double-blind trial. Changes in PRA and PRC after stopping treatment were also assessed., Methods: After placebo run-in, 842 patients (mean sitting diastolic blood pressure (BP) 95-109 mmHg) were randomised to aliskiren 150 mg or ramipril 5 mg. Dose titration and hydrochlorothiazide addition were allowed after Week 6 and 12, respectively, for inadequate BP control. Patients completing active treatment were re-randomised to current regimen or placebo during a 4-week posttreatment phase., Results: BP reductions were independent of baseline PRA at Week 12, were greater with aliskiren- than ramipril-based therapy at Week 26 (17.9/13.3 vs. 15.2/12.0 mmHg, p<0.05) and persisted for longer after stopping aliskiren. Aliskiren-based therapy reduced geometric mean PRA (-63%, p<0.05; n=103), while ramipril-based therapy increased PRA (+143%, p<0.05; n=100) at Week 26; PRC increased in both groups (aliskiren: +224% [n=33], ramipril: +145% [n=39], both p<0.05). Four weeks after stopping aliskiren-based therapy, PRA remained 52% below pre-treatment baseline; PRA returned to baseline 2 weeks after stopping ramipril-based therapy., Conclusions: Aliskiren-based therapy produced sustained BP and PRA reductions over 26 weeks; ramipril-based therapy lowered BP and increased PRA. PRA reductions persisted 4 weeks after stopping aliskiren, suggesting an inhibitory effect beyond the elimination half-life of the drug.

Both casein kinase 1 delta (CK1delta) and epsilon (CK1epsilon) phosphorylate core clock proteins of the mammalian circadian oscillator. To assess the roles of CK1delta and CK1epsilon in the circadian clock mechanism, we generated mice in which the genes encoding these proteins (Csnk1d and Csnk1e, respectively) could be disrupted using the Cre-loxP system. Cre-mediated excision of the floxed exon 2 from Csnk1d led to in-frame splicing and production of a deletion mutant protein (CK1delta(Delta2)). This product is nonfunctional. Mice homozygous for the allele lacking exon 2 die in the perinatal period, so we generated mice with liver-specific disruption of CK1delta. In livers from these mice, daytime levels of nuclear PER proteins, and PER-CRY-CLOCK complexes were elevated. In vitro, the half-life of PER2 was increased by approximately 20%, and the period of PER2::luciferase bioluminescence rhythms was 2 h longer than in controls. Fibroblast cultures from CK1delta-deficient embryos also had long-period rhythms. In contrast, disruption of the gene encoding CK1epsilon did not alter these circadian endpoints. These results reveal important functional differences between CK1delta and CK1epsilon: CK1delta plays an unexpectedly important role in maintaining the 24-h circadian cycle length.

The frog (Xenopus laevis) retina has been an important model for the analysis of retinal circadian rhythms. In this paper, several isoforms of X. laevis casein kinase I (CKI) were analyzed to address whether they are involved in the phosphorylation and degradation of period protein (PER), as they are in the circadian oscillators of other species. cDNAs encoding two splice variants of CKI(delta) (a full-length form and deletion isoform, which is missing an exon that encodes a putative nuclear localization signal and two evolutionarily conserved protein kinase domains) were isolated and analyzed, together with a previously isolated CKI(epsilon) isoform. Both CKI(delta) and CKI(epsilon) were shown to be constitutively expressed in the photoreceptors of the retina, where a circadian clock has been localized. Both the full-length CKI(delta) and CKI(epsilon) were shown to have kinase activity in vitro, and the full-length CKI(delta) phosphorylated and degraded Drosophila PER when expressed in Drosophila S2 cells. The expression and biochemical characteristics of these CKIs are consistent with an evolutionarily conserved role for CKI in the Xenopus retinal clock. The CKI(delta) deletion isoform did not exhibit kinase activity and did not trigger degradation of PER. Subcellular localization of both CKI(delta) isoforms was cytoplasmic in several cell culture lines, but the full-length CKI(delta) , and not the deletion CKI(delta) isoform, was localized to both the nucleus and the cytoplasm in Drosophila S2 cells. These results indicate that the sequences missing in the deletion CKI(delta) isoform are important for the nuclear localization and kinase activity of the full-length isoform and that one or both of these features are necessary for degradation of Drosophila PER.

The authors cloned the period (per) gene from the marine mollusk Bulla gouldiana, a well-characterized circadian model system. This allowed them to examine the characteristics of the per gene in a new phylum, and to make comparisons with the conserved PER domains previously characterized in insects and vertebrates. Only one copy of the per gene is present in the Bulla genome, and it is most similar to PER in two insects: the cockroach, Periplaneta americana, and silkmoth, Antheraea pernyi. Comparison with Drosophila PER (dPER) and murine PER 1 (mPER1) sequence reveals that there is greater sequence homology between Bulla PER (bPER) and dPER in the regions of dPER shown to be important to heterodimerization between dPER and Drosophila timeless. Although the structure suggests conservation between dPER and bPER, expression patterns differ. In all cells and tissues examined that are peripheral to the clock neurons in Bulla, bPer mRNA and protein are expressed constitutively in light:dark (LD) cycles. In the identified clock neurons, the basal retinal neurons (BRNs), a rhythm in bPer expression could be detected in LD cycles with a peak at zeitgeber time (ZT) 5 and trough expression at ZT 13. This temporal profile of expression more closely resembles that of mPER1 than that of dPER. bPer rhythms in the BRNs were not detected in continuous darkness. These analyses suggest that clock genes may be uniquely regulated in different circadian systems, but lead to similar control of rhythms at the cellular, tissue, and organismal levels.

CCAAT/enhancer-binding protein alpha (C/EBPalpha) is expressed in postmitotic, differentiated adipocytes and is required for adipose conversion of 3T3-L1 cells in culture. Temporal misexpression of C/EBPalpha in undifferentiated adipoblasts leads to mitotic growth arrest. We report here that growth arrest- and DNA damage-inducible gene 45 (gadd45) is preferentially expressed in differentiated 3T3-L1 adipocytes similar to phenotype-associated genes. Furthermore, C/EBPalpha transactivates a reporter plasmid containing 1.5 kb of the gadd45 promoter region. The proto-oncogene myc, which inhibits adipocyte differentiation, abrogates C/EBPalpha activation of gadd45. gadd45 is known to be a target of the tumor suppressor p53 in a G1 checkpoint activated by DNA damage. Immunoprecipitation of radiolabeled proteins with conformation-specific antibodies revealed that wild-type p53 is expressed throughout 3T3-L1 adipocyte development, including the postmitotic period characterized by the accumulation of gadd45 and C/EBPalpha. A stable 3T3-L1 subline was engineered to express a dominant negative p53, human p53(143ala). The p53(143ala) subline differentiated to adipocytes and showed appropriate developmental expression of gadd45. These findings suggest that postmitotic growth arrest is coupled to adipocyte differentiation via C/EBPalpha stimulation of growth arrest-associated and phenotype-associated genes.

The characterization of growth arrest-associated genes has revealed that cells actively suppress mitotic growth in response to extracellular signals. Mouse 3T3-L1 cells growth arrest at multiple distinct points during terminal differentiation to adipocytes. We examined the expression of growth arrest-specific (gas) and growth arrest- and DNA damage-inducible (gadd) genes as a function of 3T3-L1 growth arrest and adipocyte development. These growth arrest-associated genes are differentially expressed throughout adipocyte development. Some of the gas/gadd genes are preferentially expressed in a subset of growth arrest states. In contrast, gas1 and gas3 are expressed in serum-starved adipoblasts, contact-inhibited adipoblasts, and post-mitotic adipocytes. However, in post-mitotic adipocytes, gas1 and gas3 are induced in response to nutrient deprivation, not altered growth status. gas6 is an exception to the general concordance of mitotic growth arrest and gas/gadd expression in that gas6 is preferentially expressed during the clonal expansion of postconfluent adipoblasts. Combined, the expression patterns indicate that growth arrest-associated genes are regulated by numerous signal transduction pathways throughout a discrete developmental transition.