S62798, a potent TAFIa inhibitor, accelerates endogenous fibrinolysis in a murine model of pulmonary thromboembolism.

Enhancement of fibrinolysis constitutes a promising approach to treat thrombotic diseases. Venous thrombosis and thromboembolism risks are associated with increased plasma levels of TAFI (Thrombin Activatable Fibrinolysis Inhibitor) as well as its active form TAFIa. A new TAFIa inhibitor, namely S62798 has been identified. Its ability to enhance fibrinolysis was investigated both in vitro and in vivo in a mouse model of pulmonary thromboembolism, as well as its effect on bleeding. S62798 is a highly selective human, mouse and rat TAFIa inhibitor (IC50 = 11; 270; 178 nmol/L, respectively). It accelerates lysis of a human clot in vitro, evaluated by thromboelastometry (EC50 = 27 nmol/L). In a rat tail bleeding model, no effect of S62798 treatment was observed up to 20 mg/kg. Enhancement of endogenous fibrinolysis by S62798 was investigated in a mouse model of Tissue Factor-induced pulmonary thromboembolism. Intravenous administration of S62798 decreased pulmonary fibrin clots with a minimal effective dose of 0.03 mg/kg. Finally, effect of S62798 in combination with heparin was evaluated. When treatment of heparin was done in a curative setting, no effect was observed whereas a significantly decreased pulmonary fibrin deposition was observed in response to S62798 alone or in combination with heparin. This study demonstrates that S62798 is a potent TAFIa inhibitor with minimal risk of bleeding. In vivo, curative S62798 intravenous treatment, alone or associated with heparin, accelerated clot lysis by potentiating endogenous fibrinolysis and thus decreased pulmonary fibrin clots. S62798 is expected to be a therapeutic option for pulmonary embolism patients on top of anticoagulants.

Phosphinanes and Azaphosphinanes as Potent and Selective Inhibitors of Activated Thrombin-Activatable Fibrinolysis Inhibitor (TAFIa).

Selective and potent inhibitors of activated thrombin activatable fibrinolysis inhibitor (TAFIa) have the potential to increase endogenous and therapeutic fibrinolysis and to behave like profibrinolytic agents without the risk of major hemorrhage, since they do not interfere either with platelet activation or with coagulation during blood hemostasis. Therefore, TAFIa inhibitors could be used in at-risk patients for the treatment, prevention, and secondary prevention of stroke, venous thrombosis, and pulmonary embolisms. In this paper, we describe the design, the structure-activity relationship (SAR), and the synthesis of novel, potent, and selective phosphinanes and azaphosphinanes as TAFIa inhibitors. Several highly active azaphosphinanes display attractive properties suitable for further in vivo efficacy studies in thrombosis models.

Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy.

When closely related individuals mate, they produce inbred offspring, which often have lower fitness than outbred ones. Geographical exogamy, by favouring matings between distant individuals, is thought to be an inbreeding avoidance mechanism; however, no data has clearly tested this prediction. Here, we took advantage of the diversity of matrimonial systems in humans to explore the impact of geographical exogamy on genetic diversity and inbreeding. We collected ethno-demographic data for 1,344 individuals in 16 populations from two Inner Asian cultural groups with contrasting dispersal behaviours (Turko-Mongols and Indo-Iranians) and genotyped genome-wide single nucleotide polymorphisms in 503 individuals. We estimated the population exogamy rate and confirmed the expected dispersal differences: Turko-Mongols are geographically more exogamous than Indo-Iranians. Unexpectedly, across populations, exogamy patterns correlated neither with the proportion of inbred individuals nor with their genetic diversity. Even more surprisingly, among Turko-Mongols, descendants from exogamous couples were significantly more inbred than descendants from endogamous couples, except for large distances (>40 km). Overall, 37% of the descendants from exogamous couples were closely inbred. This suggests that in Inner Asia, geographical exogamy is neither efficient in increasing genetic diversity nor in avoiding inbreeding, which might be due to kinship endogamy despite the occurrence of dispersal.

Genetic and linguistic histories in Central Asia inferred using approximate Bayesian computations.

Linguistic and genetic data have been widely compared, but the histories underlying these descriptions are rarely jointly inferred. We developed a unique methodological framework for analysing jointly language diversity and genetic polymorphism data, to infer the past history of separation, exchange and admixture events among human populations. This method relies on approximate Bayesian computations that enable the identification of the most probable historical scenario underlying each type of data, and to infer the parameters of these scenarios. For this purpose, we developed a new computer program PopLingSim that simulates the evolution of linguistic diversity, which we coupled with an existing coalescent-based genetic simulation program, to simulate both linguistic and genetic data within a set of populations. Applying this new program to a wide linguistic and genetic dataset of Central Asia, we found several differences between linguistic and genetic histories. In particular, we showed how genetic and linguistic exchanges differed in the past in this area: some cultural exchanges were maintained without genetic exchanges. The methodological framework and the linguistic simulation tool developed here can be used in future work for disentangling complex linguistic and genetic evolutions underlying human biological and cultural histories.

Sex-specific genetic diversity is shaped by cultural factors in Inner Asian human populations.

OBJECTIVES: Sex-specific genetic structures have been previously documented worldwide in humans, even though causal factors have not always clearly been identified. In this study, we investigated the impact of ethnicity, geography and social organization on the sex-specific genetic structure in Inner Asia. Furthermore, we explored the process of ethnogenesis in multiple ethnic groups. METHODS: We sampled DNA in Central and Northern Asia from 39 populations of Indo-Iranian and Turkic-Mongolic native speakers. We focused on genetic data of the Y chromosome and mitochondrial DNA. First, we compared the frequencies of haplogroups to South European and East Asian populations. Then, we investigated the genetic differentiation for eight Y-STRs and the HVS1 region, and tested for the effect of geography and ethnicity on such patterns. Finally, we reconstructed the male demographic history, inferred split times and effective population sizes of different ethnic groups. RESULTS: Based on the haplogroup data, we observed that the Indo-Iranian- and Turkic-Mongolic-speaking populations have distinct genetic backgrounds. However, each population showed consistent mtDNA and Y chromosome haplogroups patterns. As expected in patrilocal populations, we found that the Y-STRs were more structured than the HVS1. While ethnicity strongly influenced the genetic diversity on the Y chromosome, geography better explained that of the mtDNA. Furthermore, when looking at various ethnic groups, we systematically found a genetic split time older than historical records, suggesting a cultural rather than biological process of ethnogenesis. CONCLUSIONS: This study highlights that, in Inner Asia, specific cultural behaviors, especially patrilineality and patrilocality, leave a detectable signature on the sex-specific genetic structure.

Design, synthesis, and biological evaluation of 1,5-benzothiazepine-4-one derivatives targeting factor VIIa/tissue factor.

The 1,5-benzothiazepine-4-one scaffold was earlier shown to provide efficient protease inhibitors. In this contribution, we describe its use in the design of factor VIIa/tissue factor inhibitors. A series containing a scaffold non-substituted on its aryl part led to compound 20 with an IC(50) of 2.16 microM. Following molecular modelling studies of this compound, a second series was prepared, which necessitated the synthesis of protected 7- or 8-substituted 1,5-benzothiazepine-4-one derivatives.

S35225 is a direct inhibitor of Plasminogen Activator Inhibitor type-1 activity in the blood.

The increased risk of thrombotic events associated with disease states such as diabetes and hypertension has been correlated with elevated circulating levels of Plasminogen Activator Inhibitor type-1 (PAI-1). In the present study we evaluate the benzothiophene derivative S35225 in comparison with two recently described inhibitors of PAI-1 activity Tiplaxtinin and WAY140312 on a panel of PAI-1 activity assays in vitro and in vivo. In a direct chromogenic assay, S35225 has an IC50 value of 44+/-0.9 microM similar to that of Tiplaxtinin (34+/-7 microM) and of WAY140312 (39+/-1 microM). In a clot lysis assay however, S35225 has a significantly lower IC50 value than Tiplaxtinin and WAY140312 (0.6+/-0.3 versus 22+/-5 and 16+/-2 microM respectively). Using a tPA capture assay to quantify active PAI-1 in rat or human plasma, neither WAY140312, nor Tiplaxtinin attained 50% inhibition of PAI-1 activity at the highest concentration tested (1 mM); S35225 has an IC50 value of 194+/-30 microM against active rat PAI-1 and 260+/-41 microM against active human PAI-1. The ability of the compounds to inhibit endogenous active PAI-1 in the rat following intravenous administration was also tested using the tPA capture assay. Only S35225 reduced circulating active PAI-1 levels in vivo (maximum inhibition of 76+/-5% at 10 mg/kg and 53+/-5% at 3 mg/kg). In contrast to Tiplaxtinin and WAY140312, S35225 is a direct inhibitor of PAI-1 activity in vitro in rat and human plasmas where vitronectin is constitutively present as well as in vivo in the blood after an intravenous administration in the rat.

Targeting ACE and ECE with dual acting inhibitors.

A series of urea analogues related to SA6817 and a GSK phosphonic acid with reported ACE inhibitory activity were prepared and tested for dual ACE and ECE activities. Although excellent ACE and NEP inhibition was achieved, only modest ECE inhibition was observed with one analogue.

Low molecular weight activated protein C inhibitors as a potential treatment for hemophilic disorders.

The synthesis and evaluation of inhibitors of activated protein C (aPC) are reported. This serine protease is partly responsible for the degradation of factor VIIIa, involved in the regulation of bleeding in hemophilia A. Benzamidine-containing derivatives were found to be potent aPC inhibitors, some of them showing selectivity against the procoagulant protease thrombin. Moreover, compound 1 significantly restored the generation of thrombin in hemophiliac plasma.

No evidence of Neandertal mtDNA contribution to early modern humans.

The retrieval of mitochondrial DNA (mtDNA) sequences from four Neandertal fossils from Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs that are not found among current humans. However, these results do not definitively resolve the question of a possible Neandertal contribution to the gene pool of modern humans since such a contribution might have been erased by genetic drift or by the continuous influx of modern human DNA into the Neandertal gene pool. A further concern is that if some Neandertals carried mtDNA sequences similar to contemporaneous humans, such sequences may be erroneously regarded as modern contaminations when retrieved from fossils. Here we address these issues by the analysis of 24 Neandertal and 40 early modern human remains. The biomolecular preservation of four Neandertals and of five early modern humans was good enough to suggest the preservation of DNA. All four Neandertals yielded mtDNA sequences similar to those previously determined from Neandertal individuals, whereas none of the five early modern humans contained such mtDNA sequences. In combination with current mtDNA data, this excludes any large genetic contribution by Neandertals to early modern humans, but does not rule out the possibility of a smaller contribution.