For the examination of the neurobiological underpinnings of highly complex mental illnesses, as is the case for schizophrenia and depression, investigations in live animals are indispensable. Until now, examinations at the neural network and behavioral level cannot be carried out in in-silico simulations or in-vitro assays, highlighting the relevance of animal model systems that allow testing hypotheses derived from epidemiological studies, which cannot be investigated in human subjects in light of obvious ethical and practical limitations. However, despite the high genetic resemblance of men and mice some mental functions, such as abstract thoughts or executive planning, are considered uniquely human. Likewise, mimicking some of the symptoms of mental disorders such as hallucinations, feelings of worthlessness and suicidal thoughts/suicide currently remain challenging in experimental animals. Considering the complexity of the pathophysiology of mental disorders, animalmodels fall into place as most useful when attempting to reconstruct single aspects of these illnesses, rather than attempting to represent the entire spectrum of symptoms associated with a given psychiatric condition . Similarly, various animalmodels of depression exist, with every individual one reflecting a slice of the pie of the entire range of the symptoms attributed to the heterogeneous clinical picture related to this complex disorder.
In conclusion, we hope to have convinced the reader that animalmodels are pivotal in the effort to translate basic progress into better care. Because of practical and ethical limitations to dissecting neurobiological disease mechanisms in humans, continued progress will critically depend on our ability to emulate aspects of depressive symptomatology and treatment response in nonhuman organisms. Still, a significant challenge remains how to effectively align variables measured in animals with those assessed in human studies, i.e., in genetic studies or during the various phases of development of novel antidepressant compounds. This can only be achieved if translation is prospectively planned, allowing for the best possible match of recorded data across species. Translational psychiatry is a two-way bridge: research questions ideally emerge as a well- defined, clinically relevant problem that needs to be carefully translated into the best-possible animal experimental approach. On the other hand, preclinical research needs to inform clinical trials and diagnosis. Recent successful examples in depression
Abstract A most precise determination of the postmortem interval (PMI) is a crucial aspect in forensic casework. Although there are diverse approaches available to date, the high heterogeneity of cases together with the respective postmortal changes often limit the validity and sufficiency of many methods. Recently, a novel approach for time since death estimation by the analysis of postmortal changes of muscle proteins was proposed. It is however necessary to im- prove the reliability and accuracy, especially by analysis of possible influencing factors on protein degradation. This is ideally investigated on standardized animalmodels that, how- ever, require legitimization by a comparison of human and animal tissue, and in this specific case of protein degradation profiles. Only if protein degradation events occur in compara- ble fashion within different species, respective findings can sufficiently be transferred from the animal model to applica- tion in humans. Therefor samples from two frequently used animalmodels (mouse and pig), as well as forensic cases with representative protein profiles of highly differing PMIs were analyzed. Despite physical and physiological differences be- tween species, western blot analysis revealed similar patterns in most of the investigated proteins. Even most degradation events occurred in comparable fashion. In some other aspects, however, human and animal profiles depicted distinct differ- ences. The results of this experimental series clearly indicate the huge importance of comparative studies, whenever animal
In the rat model, systemically applied MCT induces endothelial inflammation with a structural remodelling of the lung arteries leading to pulmonary hypertension and similar histological changes like PAH in humans. The inflammatory mechanisms appear to play a significant role in some types of PH, including human types of PH. 36 The MCT rat model has become one of the most widely used animalmodels to study various aspects of PH. 33 Rats exposed to MCT develop an acute pulmonary vascular inflammatory reaction with subsequent remodelling including pulmonary artery smooth muscle hypertrophy, leading to a persistent severe pulmonary hypertension after 3 to 4 weeks. 37-39 This is a reproducible and well-established model of the disease which may be of value for investigating some aspects of this condition. 40 For instance, pulmonary vascular inflammation seems to play a key role in subjects developing pulmonary arterial hypertension in the context of toxic oil syndrome, autoimmune diseases, or infectious conditions. 41 Pulmonary vascular inflammation may also play a key role in a subset of patients with idiopathic pulmonary hypertension. However, the development of the medial hypertrophy revealed that it is preceded by intense metabolic activity and proliferation of the pulmonary endothelial cell layer. 41
In order to develop preventive treatment in HD it is important to determine early manifestations of the disease prior to traditional clinical diagnosis. Findings from the Predict-HD 2 study suggest that the commencement of detectable and measurable changes appear one to two decades before the predicted time of clinical diagnosis (Duff et al. 2010; Paulsen et al. 2008). Cognitive deficits are one of the triad of HD symptoms and includes impairments in attention, verbal fluency, executive and visuospatial functioning (Ho et al. 2003). Reports in pre-manifest HD or at-risk carriers have showed progressive cognitive impairment 2 to 12 years before the development of manifest motor disease (Foroud et al. 1995; Jason et al. 1988; Paulsen et al. 2001). These findings suggest that detecting robust cognitive deficits early on in animalmodels for HD may be valuable to help finding potential prophylactic drugs. Although many studies have been conducted in animalmodels for HD, most of these have focussed on motor symptoms rather than cognitive deficits, possibly because motor symptoms are easier to assess in rodents. In order to optimize our chances of developing meaningful therapies, some aspects need to be taken into consideration: (1) because HD is a time- dependent disorder, it is important to use species that model these aspects of timing. Fragment rodent models exhibit striatal atrophy and rapid onset phenotype; but they do not express the full length huntingtin protein that should replicate the human condition and some of the models (most notably the R6/2 model) exhibit such rapid symptom development that it becomes almost impossible to study presymptomatic animals. Given the generally short life-span of rodents (typically around 2 years), one might suggest other genetic models such as pigs, sheep and monkey could more optimally mimic the pathological features seen in patients (Jacobsen et al. 2010; Matsuyama et al. 2000; Yang et al. 2008). However, these models have other limitations especially in terms of practical issues (laboratory space, pricing) and the fact that few cognitive tests have specifically been developed for such large animals. In contrast to the above
Alzheimer’s disease is the most common cause of dementia and accompanied by vast socio- economic problems. To meet these challenges, basic research makes great efforts to provide a better understanding and develop treatment strategies. However, the final success depends also on the quality and precision of the utilised disease models. To reproduce the disease state in animals, mutant human transgenes are overexpressed. Although most animals still express the endogenous variants, the potential interactions with transgenic proteins have rarely been addressed so far. This study was conducted to provide new insights on the impact of endogenous proteins on deposition of the corresponding transgenic proteins in animalmodels of neurodegenerative diseases. To do so, an established model of cortical amyloidosis expressing mutant human variants of amyloid precursor protein (APP) and presenilin 1 was crossed with an APP knockout strain to create a model that exclusively expresses human APP. The absence of murine APP led to an increased number of cortical plaques and higher levels of cerebral Aβ. In contrast, accumulation of amyloid in leptomeningeal blood vessels was diminished. Deficiency of murine APP further altered cellular response to amyloid deposition, as animals developed a pronounced, age-dependent astrogliosis and presented with significantly reduced microglial coverage of plaques. Neuronal density, caspase levels and expression of APP- and Aβ-processing enzymes were unchanged within the analysed period. Nevertheless, these mice are genetically modified and rather mimic the rare inherited form of the disease. The most promising model for the common sporadic variant is the South American rodent
As TNC is known to be involved in inflammatory and fibrotic processes, we explored the presence of inflam- matory process through TLR4 expression at the valvu- lar level. Indeed, we observed in the animalmodels an TLR4 expression upregulation in leaflets from ischemic MR groups. TLR4 is a member of the Toll-like receptor family. It can be activated either by exogeneous stimuli or as a response to internal damage cues [ 9 , 18 ]. Its activation leads to a cascade of inflammatory responses, which repre- sents the first line of innate host defense. TLR4 expression at the valvular level was significantly higher after 6 weeks. Even though TLR4 expression persisted at 6 months, the percentage of cells expressing TLR4 was lower compared to the early time-point. This would suggest that the inflam- matory process activated at an early time-point resulted in a counterproductive fibrosis as shown by the leaflet thickness and length evolution in these animals. TLR4 persistence at lower amounts might have contributed to the fibrotic process, resulting in thicker leaflets with no increase in their area. TLR4 can be expressed by various cell types including macrophages. Future studies will be needed to clarify whether macrophages have a role in val- vular remodeling.
Inflammatory skin diseases cover a wide range of skin conditions that cause dry, itchy, scaly skin and affects millions around the world. Current therapies are mostly symptomatic and often associated with a wide range of side effects. Therefore, there is a growing need for a more specific therapy targeting key molecules in the pathogenesis of such diseases. Investigations revealed a central role for different T helper subsets in the immunopathology of these skin diseases. Atopic dermatitis (Th2), contact dermatitis (Th1) and Psoriasis (Th1, Th17), are associated with one or more of these Th- phenotypes. The differentiation and activation of T helper subtypes is regulated by different transcription factors. This study focused on two specific transcription factors GATA3 and Tbet, which regulate the differentiation and activation of Th2 and Th1, respectively. The levels of these transcription factors were found to be elevated in diseases with the respective Th phenotype, which made them interesting targets for DNAzyme-based therapy. In order to test the efficacy of such transcription factor-specific DNAzymes, two different animalmodels of inflammatory allergic skin diseases were established. In the first model skin injury and the hapten oxazolone were used to elicit a Th2-dominant contact hypersensitivity with features similar to those of atopic dermatitis. In the second model, Ovalbumin was used to induce a Th1-dominated inflammation in OVA-specific T cell receptor- transgenic mice after systemic sensitization with OVA/CFA. Effects of topical preventive treatment with GATA3-specific DNAzyme (hgd40) were investigated in the oxazolone model. The DNAzymes were formulated in w/o/w emulsion for protection against degradation and an enhanced skin penetration. Compared to placebo and control non-specific DNAzyme ODNg3, prophylactic treatment with hgd40 significantly reduced skin swelling. It also resulted in lower numbers of CD4 + cells
* Department of Anesthesiology, RWTH Aachen University Hospital, Aachen, Germany; and † Department
of Anesthesiology and Intensive Care, Istanbul Faculty of Medicine, University of Istanbul, Istanbul, Turkey Received 7 Dec 2016; first review completed 28 Dec 2016; accepted in final form 13 Feb 2017
ABSTRACT —Several direct oral anticoagulants (DOACs), including direct thrombin and factor Xa inhibitors, have been approved as alternatives to vitamin K antagonist anticoagulants. As with any anticoagulant, DOAC use carries a risk of bleeding. In patients with major bleeding or needing urgent surgery, reversal of DOAC anticoagulation may be required, presenting a clinical challenge. The optimal strategy for DOAC reversal is being refined, and may include use of hemostatic agents such as prothrombin complex concentrates (PCCs; a source of concentrated clotting factors), or DOAC-specific antidotes (which bind their target DOAC to abrogate its activity). Though promising, most specific antidotes are still in development. Preclinical animal research is the key to establishing the efficacy and safety of potential reversal agents. Here, we summarize published preclinical animal studies on reversal of DOAC anticoagulation. These studies (n ¼ 26) were identified via a PubMed search, and used rodent, rabbit, pig, and non-human primate models. The larger of these animals have the advantages of similar blood volume/hemodynamics to humans, and can be used to model polytrauma. We find that in addition to varied species being used, there is variability in the models and assays used between studies; we suggest that blood loss (bleeding volume) is the most clinically relevant measure of DOAC anticoagulation-related bleeding and its reversal. The studies covered indicate that both PCCs and specific reversal agents have the potential to be used as part of a clinical strategy for DOAC reversal. For the future, we advocate the development and use of standardized, clinically, and pharmacologically relevant animalmodels to study novel DOAC reversal strategies.
As already mentioned, animalmodels of PD serve as valuable tools for experimental scientists in their ambition to elucidate the underlying pathophysiological mechanisms as well as in their attempts to design new and more efficient treatment strategies for the disease (Blesa and Przedborski, 2014; Le et al., 2014). However, animalmodels prove to be useful just to the extent to which they properly simulate the pathological, histological, biochemical as well as functional characteristics of the disorder (Duty and Jenner, 2011; Jenner, 2008a). An ideal animal model of PD would preferably show both the behavioural as well as pathophysiological features of the disease, including motor and non-motor disturbances, progressive degeneration of dopaminergic and non-dopaminergic neurons as well as Lewy body-like inclusions. It should meet the following crucial requirements: 1) face validity which reflects the analogy in symptoms and pathological features between the animal model and human patients, 2) construct validity which shares etiology and underlying pathophysiological mechanisms and 3) predictive validity which suggests that treatment strategies that are effective in the model will also be successful in human patients (Morsink and Dukers, 2009; van der Staay et al., 2009). An example of characteristics for the validation of an ideal animal model of PD is illustrated in Figure 6.
Small animalmodels—Two studies have used a rabbit model to evaluate factor concentrates for apixaban reversal. In both studies, administration of apixaban resulted in sig- nificant increases in bleeding parameters. While Herzog et al. (61) found significant reductions in blood loss and bleeding time (both primary endpoints) when dosing apixaban-anti- coagulated rabbits with 4F-PCC (Beriplex; 12.5 U/kg), Martin et al. did not find reductions in blood loss in apix- aban-anticoagulated rabbits dosed with 4F-PCC (Kanokad; 60 U/kg) or rFVIIa (240 mg/kg). Indeed, the latter group found increased blood loss when FC (300 mg/kg) was tested for anticoagulation reversal (62). However, apixaban only increased bleeding 1.4-fold in the study from Martin et al., which may have limited the scope to detect reversal (by contrast, Herzog et al. used a higher apixaban dose, which increased the bleeding volume approximately 11-fold, suggesting that injury type and severity may play a role in identifying treatment effects).
Osteoporosis is one of the emerging health problems of aging societies in developed countries. It is estimated that 200 million people worldwide suffer from osteo- porosis and the incidence is still growing. 40 Currently, one out of three women and one out of five men aged over 50 years will experience an osteoporotic fracture during their life. 41 Osteoporotic fractures are commonly located in bone regions with a high proportion of tra- becular bone including the vertebral bodies, the distal radius and the proximal femur, because bone loss starts in these metabolically active bone regions. 42 The treatment and healing of osteoporotic fractures is often associated with orthopaedic complications. These can result from implant anchorage problems in the fragile bone and/or from the disturbed healing capacity of the bone tissue itself. 42–46 There is need for suitable animalmodels to test newly developed implants and bio- materials on the one hand and on the other hand to better understand the poor bone healing capacity and delayed fracture healing on a cellular and molecular level. 2 Generally, animalmodels to investigate the os- teoporotic fracture healing process should reflect the clinical scenario of bone loss, for example, post- menopausal, senile, or secondary osteoporosis. Fur- thermore, the animal model should allow the generation of metaphyseal fractures.
the BB.4S rat develop an incomplete metabolic syndrome with obesity, hyperleptinemia, and dyslipidemia, as compared to their progenitor strain, the diabetes-prone BB/OK rat (8). Because the metabolic syndrome – like type 1 diabetes – is multifactorial, where each single facet is complex and polygenetically inherited, animalmodels are necessary to differentially analyze the co-morbidities of this complex disease. The incomplete metabolic syndrome found in BB.4S offered the chance to narrow down the region leading to metabolic disorders. Therefore, congenic BB.4S sublines with smaller regions, termed BB.4Sa and BB.4Sb, were generated to increase the chance of finding gene(s) involved in the development of metabolic facets. By the longitudinal characterization of congenic BB.4S and their subcongenic derivatives BB.4Sa and BB.4Sb, it was possible to cluster the traits and simultaneously assign them to a chromosomal region flanked by microsatellite markers. Some traits were significantly higher (serum triglycerides and leptin) or lower (serum total cholesterol, HDL- cholesterol ratio, glucose tolerance shown as area under the curve: AUC) in BB.4S rats than in their subcongenic derivatives. In addition, some traits (body weight gain, serum insulin, adiposity index-AI) could be grouped together. In the first two groups, genes responsible for an increase or decrease of these values must be located in the region which is different from BB.4S, but comparable between both subcongenic lines. This common region is flanked by microsatellite markers D4Got72 and Tacr1 (8). Gene(s) responsible for body weight gain, which was comparable between all three rat lines, must be of SHR origin and therefore should be located between D4Got41 and Ian4. Gene(s) in this region influencing serum insulin – the values of which in BB.4Sb rats were significantly lower than in BB.4S and BB.4Sa –should be located between D4Rat168 and D4Rat171, for this region in BB.4Sb differs genetically from both BB.4Sa and BB.4S. The region is of BB origin in BB.4Sb and of SHR origin in BB.4Sa and BB.4S. No clear-cut relationship was found for AI. The graduated decrease from BB.4S to BB.4Sa to BB.4Sb seems to suggest an interaction of genes.
Fe-EDTA, Ca-EDTA and Na-EDTA had generally been considered safe, with the No Observed Adverse Effect Level (NOAEL, defined as the concentration under which no adverse effects were observed in comparison to control in toxicologic studies in animals) in mice and rats determined at 250 mg Fe-EDTA/kg bw in experimental studies.  The Acceptable Daily Intake (ADI) in humans as stated the European Food Safety Authority (EFSA) was calculated at 1.9 mg/kg bw ; ADI is defined as the concentration which does not cause adverse effects in long-term/lifelong everyday exposure and can therefore be used in food products; ADI is calculated from NOAEL using conversion factors which account for inter- and intraspecies variation as well as the difference in body weight/body surface ratio between humans and the animal species used to determine NOAEL.
but decreased MR expression in the female guinea pig and in the rat offspring as well as in the fetal mouse. GR expression in the hippocampus following maternal treatment was increased in female guinea pig and decreased in rat offspring but synthetic glucocorticoids showed no effect on MR or GR expression in the hippocampus of the human fetus during midgestation [121, 227, 255, 329, 442, 490]. In addition, antenatal synthetic glucocorticoid treatment of the mother decreased the CRH expression in the PVN of the fetal guinea pig and the neonatal rat but increased the CRH expression in the adults‘ rat hypothalamus [68, 285, 431], increased the human ACTH response to stress , and decreased the expression of adrenal steroid enzymes in guinea pigs . Exposure to synthetic glucocorticoids during gestation caused elevated plasma basal and stimulated cortisol concentrations in the rhesus monkey offspring and a blunted salivary cortisol response to stress in human babies and infants [114, 115, 469]. Besides these direct impacts on the offspring’s limbic- hypothalamic-pituitary-adrenal (LHPA) axis, antenatal synthetic glucocorticoid administration to the mother decreased the passage of maternal glucocorticoids through the placenta into the fetus in baboons while maternal stress increased the passage into the rat [258, 262]. In humans, the exposure to increased glucocorticoid concentrations or an early adverse environment is correlated in the fetus with a reduction in birth weight, and in infants with altered affective reactivity to novelty and symptoms analogous to the attention-deficit hyperactivity disorder (ADHD) [116, 157, 308]. The inconsistent results in the response of different animal species to early adversity can be explained to some extent by the species-specific differences in maturational status of the LHPA axis during exposure and a comparison between species might be determined by the timing of the impact in relation to the gestational length [278, 282]. It can be assumed that depending on the mentioned effects during development, environmental programming activates or deactivates the HPA axis and increases the risk of disorders related to hyper- and hypocortisolism, such as anxiety, depression and metabolic diseases .
The manifold impact of vitamin A and D on im- mune cell responses and profound evidence from animal studies provide hope that these molecules can help control allergy. More randomized controlled human studies are needed to underpin the potential of these vitamins and their metabolites in prevention or therapy of Th2-dominant allergic diseases includ- ing asthma. We propose that more emphasis should be put on the determination of the vitamin status of allergic patients and, especially for vitamin D, on prophylaxis in early life or during pregnancy.
el findings are secondary changes due to progressive cell damage preceding overt cardiomyopathy in the disease course still remains a matter of debate. Another interesting study was published by Onopiuk et al. dealing with metabolic alterations in immortalized mdx mouse (SC-5) myoblasts (Onopiuk, Brutkowski et al. 2009). The most striking findings of this study were substantially lower levels of oxygen consumption, expression of respiratory complexes III and V, but similar rates of total cellular ATP content in mdx my- oblasts, compared to dystrophin-positive control (IMO) myoblasts, thus indicating a shift from oxidative to glycolytic metabolism, a finding which is quite contradictory to the metabolic profile of dysferlin- deficient myotubes and mice models. These experiments were further underpinned by studies conducted by Even et al. here investigating the glucose uptake and heat production rate, as a marker for mitochon- drial respiration in EDL and SOL muscles derived from mdx and wildtype (C57BL/10) mice (Even, Decrouy et al. 1994). Whereas basal and insulin stimulated 2-deoxy-glucose (2DG) glucose uptake values were similar between mdx and wildtype mice, there was a marked decrease in basal heat production upon incubation with glucose, indicating that despite normal glucose uptake kinetics, an impairment in the downstream glycolytic pathway or TCA-cycle leads to an altered metabolic profile in mdx mice. These studies focussing on metabolic alterations in the mdx mouse model for muscular dystrophy are compara- ble to our data obtained with this mouse model upon the GC/MS based metabolic profiling analysis. Con- sistent with data published by Kairallah et al., we detected an increased levels of glycolytic intermediates in glycolytic and mixed fibre type muscles (TA and QUAD), pointing towards an enhanced glycolytic flux presumably due to an upregulation of glucose uptake. Furthermore, lactate levels were also found to be elevated as TA and partly QUAD muscle support a rather anaerobic glucose metabolism. Interestingly, 2-ketoglutaric acid levels were markedly increased in TA and QUAD muscle, possibly due to anaplerotic reactions activated in these muscles. SOL muscle, consisting of type I muscle fibres on the other hand exhibited a glycolytic metabolite pattern contrary to TA and QUAD muscle with significantly decreased levels of phosphorylated hexoses and lactate, whereas TCA-cycle metabolite expression patterns resem- bled the fibre type counterpart.
This is reflected by the loss of α-dystroglycan, which is an important anchor protein, linking the astrocyte processes with the molecules of the extracellular matrix of the perivascular space, and which is also involved in aquaporin clustering at the glia limitans. It is well established that α-dystroglycan is selectively cleaved at the parenchymal basement membrane at sites of leukocyte extravasation in EAE (Agrawal et al., 2006). However, in simple EAE models, this cleavage does not seem to translate to a complete loss of α-dystroglycan reactivity in the lesions. Collagen 4, too, is at least in part a marker for the intactness of the perivascular glia limitans. It is also produced by astrocytes and under normal conditions deposited in a polarized manner on the astrocytic surface of the glia limitans. We show here, that collagen 4 is expressed in the cytoplasm of reactive astrocytes and excreted into the parenchymal extracellular space of the CNS tissue, when the structur of the glia limitans is impaired. In addition it decorates the surface of reactive astrocytes within the lesions, which may further disturb astrocyte function.