Rhesus Monkey Model Research Articles

Hyperbilirubinemia models caused by hemolysis in newborn rhesus monkeys

Objective To establish the newborn rhesus monkey model of hemolytic hyperbilirubinemia and provide an experimental basic model for research of hyperbilirubinemia. Methods Sixteen 3-day old newborn rhesus monkeys were divided into experimental group and control group, with 8 newborn rhesus monkeys in each group.Eight newborn rhesus monkeys in experimental group were treated with intravenous injection of 10 g/L phenylhydrazine hydrochloride(50 mg/kg) to establish model of homolytic hyperbilirubinemia.The newborn rhesus monkeys in control group were treated with intravenous injection of 9 g/L saline at the same time.Twenty-four hours and 48 hours after the experimental treatment, the bilirubin in blood was detected to evaluate the models, and the clinical manifestations of newborn rhesus monkeys with hyperbilirubinemia were recorded by using monitoring equipment.The brain slices were made to evaluate the model in 1 dead monkeys of experimental group. Results The newborn rhesus monkey of experimental group showed obvious skin, sclera jaundice and hemoglobinuria.The serum total bilirubin [(252.76±63.42) μmol/L], unconjugated bilirubin[(165.85±44.93) μmol/L] and conjugated bilirubin [(87.16±21.22) μmol/L] in the experimental group were significantly higher than those [(20.62±5.72) μmol/L, (7.93±2.31) μmol/L, (12.51±3.53) μmol/L] in the control group, and the differences were statistically significant (t=14.581, 13.881, 14.040, all P<0.01). The level of hemoglobin [(47.18±10.09) μmol/L] in the experimental group was significantly lower than that of the control group [(136.85±13.48) μmol/L], and the difference was statistically significant (t=-21.308, P<0.01). The results of pathological showed brain edema, rupture and eosinophilic and bilirubin deposition in the basal nuclei, and necrosis appeared in some severe parts.And there were different degrees of retardation and coordination disorders in the experimental group's newborn rhesus monkeys, but gradually returned to normal in 4 months later. Conclusion Intravenous injection of phenylhydrazine hydrochloride can be used to produce newborn rhesus monkey models of hemolytic hyperbilirubinemia. Key words: Hyperbilirubinemia; Phenylhydrazine hydrochloride; Hemolysis; Animal model

Immunogenicity of a plasmid DNA vaccine encoding 42 kDa fragment of Plasmodium vivax merozoite surface protein-1

Plasmodium vivax is the second major human malaria parasite that inflicts debilitating morbidity and consequent economic impact in South-East Asian countries. The relapsing nature of P. vivax along with the emergence of drug-resistant P. vivax strains has emphasized the urgent need for a vaccine. However, the development of an effective vivax vaccine is seriously hampered due to the diversity and variation in parasite antigens and non-availability of suitable animal models. DNA based vaccines represent an alternative approach in inducing immunity to multiple targets from different stages of malaria parasite. DNA prime-boosting strategies induce both antibody mediated and cell-mediated immune responses that are the major mechanisms of protection against malaria parasites. We have earlier studied the immunogenicity and protective efficacy of the soluble and refolded forms of recombinant 42kDa fragment of Plasmodium vivax merozoite surface protein-1 (PvMSP-142) using P. cynomolgi rhesus monkey model. In the present study, we have constructed a recombinant DNA vaccine encoding 42kDa fragment of P. vivax MSP-1 and studied the immunogenicity of PvMSP-142 DNA vaccine construct in mice. The 42kDa gene fragment of PvMSP-1 was PCR amplified using gene specific primers and subcloned into pcDNA 3.1 (+) eukaryotic expression vector. In vitro expression of PvMSP-142 plasmid construct was checked by transfection in COS-1 cell line. Indirect immunofluorescence of transfected COS-1 cells probed with monoclonal antibodies against PvMSP-142 exhibited positive fluorescence. Immunization of BALB/c mice with PvMSP-142-pcDNA vaccine construct revealed the immunogenicity of recombinant vaccine plasmid that can be enhanced by prime boosting with recombinant protein corresponding to the DNA vaccine as evidenced by significant elevation of antibody and the cytokines responses.

Combining Diffusion Tensor Imaging and Susceptibility Weighted Imaging on the Substantia Nigra of 1-Methyl-4-Phenyl-1, 2, 3, 6-Tetrahydropyridine (MPTP)-induced Rhesus Monkey Model of Parkinson's Disease.

The aim of this study was to evaluate whether combining diffusion tensor magnetic resonance imaging (DTI) and susceptibility weighted imaging (SWI) techniques would provide a sensitive method for differentiating between 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced rhesus monkey model of Parkinson's disease (PD) and wild-type controls. Seventeen rhesus monkeys were divided into two groups. A series of intramuscular injections of either saline (control group, n = 8) or MPTP (0.2 mg/kg body weight; PD group, n = 9) were given to the monkeys, twice a week. Then, SWI and DTI scans were obtained from the monkeys with Siemens Magnetom Verio 3.0T superconductive MRI system. Region of interest analysis was performed on substantia nigra pars compacta (SNc) and substantia nigra pars reticulata (SNr). In addition, immunohistochemical staining of tyrosine hydroxylase was applied to assess degeneration of SN dopaminergic neurons. Monkeys in the PD group displayed mild to moderate motor symptoms assessed using Kurlan's scale. With SWI scans, decreased width of SNc but increased width of SNr was found in PD group monkeys compared to controls. Calculation of the ratios of widths of SNc and SNr to the anterior and posterior mesencephalic diameter also reflected narrower SNc but wider SNr than controls. Decreased SWI signal intensity of SNc and SNr suggested iron deposition in both subregions of SN. The DTI scans showed lower fractional anisotropy (FA) values in SNc of the PD group monkeys, while no change of FA values in SNr was detected. Immunohistochemical test displayed generalized loss of dopaminergic neurons in SN of PD group monkeys. Combining the use of DTI and SWI can provide a sensitive method for differentiating between MPTP-induced rhesus monkey model of PD and wild-type controls. This effective imaging modality might provide additional information for characteristic identification of PD at early stages, thus enhancing the ability to make early diagnosis, and monitor progression of the natural history and treatment effects.

Organ Targeted Copper Delivery Reverses Fibrosis in Rhesus Monkey Model of Myocardial Ischemic Infarction

Excessive collagen deposition post myocardial ischemic injury hastens heart failure. Copper supplementation significantly improved cardiac function and reduced fibrosis in myocardial ischemic infarction. The present study was undertaken to understand the link between the reduced fibrosis and the recovery of cardiac function. Male Rhesus monkeys of 4–5 years old were subjected to coronary artery ligation to induce myocardial infarction. At the end of fourth weeks after the surgery, ultrasound contrast microbubble composed of Cu‐albumin coating for cardiac organ‐specific Cu delivery through ultrasound manipulation was used to treat the monkeys twice a week for other four weeks. Collagen deposition in the infarct hearts was observed 4 weeks and further enhanced 8 weeks after ischemia. The collagen content in the infarct myocardium was not changed significantly after Cu treatment. However, type I and III collagen mRNA levels were decreased, and collagen network became loosened, along with an increase in the capillary density. Lysyl oxidase (LOX), an enzyme related to collagen deposition, was increased, and metalloproteinase‐1 (MMP‐1), an enzyme involved in collagen degradation, was decreased in the infarct area relative to sham operated control and remote area. After Cu treatment, MMP‐1 was significantly increased, and the ratio between MMP‐1/LOX was dramatically elevated. These results thus suggest Cu‐induced MMP‐1 elevation in the infarct area is mostly likely responsible for the breakage of collagen cross‐linking leading to diminished collagen deposition and improved angiogenesis and recovery of cardiac function.Support or Funding InformationThis study is supported by National Science Foundation of China (81230004 and 81300109).

Therapeutic efficacy of the small molecule GS-5734 against Ebola virus in rhesus monkeys.

The most recent Ebola virus outbreak in West Africa, which was unprecedented in the number of cases and fatalities, geographic distribution, and number of nations affected, highlights the need for safe, effective, and readily available antiviral agents for treatment and prevention of acute Ebola virus (EBOV) disease (EVD) or sequelae. No antiviral therapeutics have yet received regulatory approval or demonstrated clinical efficacy. Here we report the discovery of a novel small molecule GS-5734, a monophosphoramidate prodrug of an adenosine analogue, with antiviral activity against EBOV. GS-5734 exhibits antiviral activity against multiple variants of EBOV and other filoviruses in cell-based assays. The pharmacologically active nucleoside triphosphate (NTP) is efficiently formed in multiple human cell types incubated with GS-5734 in vitro, and the NTP acts as an alternative substrate and RNA-chain terminator in primer-extension assays using a surrogate respiratory syncytial virus RNA polymerase. Intravenous administration of GS-5734 to nonhuman primates resulted in persistent NTP levels in peripheral blood mononuclear cells (half-life, 14 h) and distribution to sanctuary sites for viral replication including testes, eyes, and brain. In a rhesus monkey model of EVD, once-daily intravenous administration of 10 mg kg(-1) GS-5734 for 12 days resulted in profound suppression of EBOV replication and protected 100% of EBOV-infected animals against lethal disease, ameliorating clinical disease signs and pathophysiological markers, even when treatments were initiated three days after virus exposure when systemic viral RNA was detected in two out of six treated animals. These results show the first substantive post-exposure protection by a small-molecule antiviral compound against EBOV in nonhuman primates. The broad-spectrum antiviral activity of GS-5734 in vitro against other pathogenic RNA viruses, including filoviruses, arenaviruses, and coronaviruses, suggests the potential for wider medical use. GS-5734 is amenable to large-scale manufacturing, and clinical studies investigating the drug safety and pharmacokinetics are ongoing.

In Vivo Confocal Microscopic Evaluation of Corneal Endothelial Dysfunction Induced by Phacoemulcification in Rhesus Monkey Models.

To observe the characteristic morphological changes of corneal endothelial dysfunction induced by phacoemulcification in rhesus monkey models under confocal microscope. The corneal endothelial dysfunction models were established by phacoemulcification power on the central corneal of 7 to 9 mm diameter in the right eyes of 4 rhesus monkeys (the modeling group). The left eyes of 4 rhesus monkeys were set as blank control group. The structural changes in different corneal layers were evaluated by slit lamp microscope and in vivo confocal microscope before surgery and 1, 2, 3, and 4 weeks after surgery. SPSS 19.0 software was applied to analyze data. Paired-t test was used to compare the number of nerve plexus in Bowman's layer and corneal endothelial cell density. Analysis of variance (ANOVA) was used to analyze corneal thickness. After phacoemulcification, the changes of cornea occurred gradually in the endothelial layer, stroma, Bowman's membrane, and basal epithelial layer. In the early stage, the interspace of corneal endothelial cells enlarged and few activated stromal cells were detected in the stroma. The cell morphology of stroma altered. The thickness of stroma increased. Two weeks after surgery, the nerve plexus in Bowman's layer decreased and edema of stroma and endothelial layer increased. Three weeks after surgery, the interspace of basal epithelial cells increased with a few Langerhans' cells infiltration and edema of stroma and endothelial layer increased. Four weeks after the surgery, a large amount of Langerhans' cells presented in basal epithelial layer. Only a few nerve lexus could be seen in Bowman's layer. The stroma and endothelial cells had severe edema. A large number of activated stromal cells could be found in stromal layer. Two weeks after the surgery, the number of nerve plexus in Bowman's layer (t=6.9192, P=0.002) and corneal endothelial cell density (t=7.8936, P<0.0001) in the modeling group were significantly lower than that in control group. Compared with corneal thickness in control group, it was significantly larger in the modeling group at 1 (t=28.31, P<0.0001), 2 (t=63.56, P<0.0001), 3 (t=123.22, P<0.0001), and 4 weeks (t=180.80, P<0.0001) after the surgery. The changes in corneal endothelial dysfunction induced by phacoemulcification in rhesus monkey models can be clearly shown under in vivo confocal microscope. Gradual increase of endothelial cells interspace, activated stromal cells, increase of Langerhans' cells, and decrease of plexus in Bowman's layer are the main changes.

Evaluation of the Differences of Myocardial Fibers between Acute and Chronic Myocardial Infarction: Application of Diffusion Tensor Magnetic Resonance Imaging in a Rhesus Monkey Model

ObjectiveTo understand microstructural changes after myocardial infarction (MI), we evaluated myocardial fibers of rhesus monkeys during acute or chronic MI, and identified the differences of myocardial fibers between acute and chronic MI.Materials and MethodsSix fixed hearts of rhesus monkeys with left anterior descending coronary artery ligation for 1 hour or 84 days were scanned by diffusion tensor magnetic resonance imaging (MRI) to measure apparent diffusion coefficient (ADC), fractional anisotropy (FA) and helix angle (HA).ResultsComparing with acute MI monkeys (FA: 0.59 ± 0.02; ADC: 5.0 ± 0.6 × 10-4 mm2/s; HA: 94.5 ± 4.4°), chronic MI monkeys showed remarkably decreased FA value (0.26 ± 0.03), increased ADC value (7.8 ± 0.8 × 10-4mm2/s), decreased HA transmural range (49.5 ± 4.6°) and serious defects on endocardium in infarcted regions. The HA in infarcted regions shifted to more components of negative left-handed helix in chronic MI monkeys (-38.3 ± 5.0°–11.2 ± 4.3°) than in acute MI monkeys (-41.4 ± 5.1°–53.1 ± 3.7°), but the HA in remote regions shifted to more components of positive right-handed helix in chronic MI monkeys (-43.8 ± 2.7°–66.5 ± 4.9°) than in acute MI monkeys (-59.5 ± 3.4°–64.9 ± 4.3°).ConclusionDiffusion tensor MRI method helps to quantify differences of mechanical microstructure and water diffusion of myocardial fibers between acute and chronic MI monkey's models.

The association of depressed angiogenic factors with reduced capillary density in the Rhesus monkey model of myocardial ischemia.

Depressed capillary density is associated with myocardial ischemic infarction, in which hypoxia-inducible factor 1α (HIF-1α) is increased. The present study was undertaken to examine changes in the angiogenic factors whose expression is regulated by HIF-1 and their relation to the depressed capillary density in the Rhesus monkey model of myocardial ischemic infarction. Male Rhesus monkeys 2-3 years old were subjected to myocardial ischemia by permanent ligation of left anterior descending (LAD) artery leading to the development of myocardial infarction. Eight weeks after LAD ligation, copper concentrations, myocardial histological changes and capillary density were examined, along with Western blot and immunohistochemical analysis of angiogenic factors and detection of HIF-1 activity. Capillary density was significantly decreased but the concentrations of HIF-1α and HIF-1β were significantly increased in the infarct area. However, the levels of mRNA and protein for VEGF and VEGFR1 were significantly decreased. Other HIF-1 regulated angiogenic factors, including Tie-2, Ang-1 and FGF-1, were also significantly depressed, but vascular destabilizing factor Ang-2 was significantly increased. Copper concentrations were depressed in the infarct area. Copper-independent HIF-1 activity was increased shown by the elevated mRNA level of IGF-2, a HIF-1 target gene. Removal of copper by a copper chelator, tetraethylenepentamine, from primary cultures of neonatal rat cardiomyocytes also suppressed the expression of HIF-1 regulated VEGF and BNIP3, but not IGF-2. The data suggest that under ischemic conditions, copper loss suppressed the expression of critical angiogenic genes regulated by HIF-1, but did not affect copper-independent HIF-1 activation of gene expression. This copper-dependent dysregulation of angiogenic gene expression would contribute to the pathogenesis of myocardial ischemic infarction.

Clinical efficacy of a new CD28-targeting antagonist of T cell co-stimulation in a non-human primate model of collagen-induced arthritis.

T cells have a central pathogenic role in the aetiopathogenesis of rheumatoid arthritis (RA), and are therefore a favoured target of immunotherapy aiming at physical or functional elimination. Here we report an efficacy test of FR104, a new co-stimulation inhibitor directly targeting CD28 on T cells, in a translationally relevant model, the rhesus monkey model of collagen-induced arthritis (CIA). As a relevant comparator we used abatacept [cytotoxic T lymphocyte antigen immunoglobulin (CTLA Ig)], an antagonist of CTLA-4 binding to CD80/86 clinically approved for treatment of RA. Treatment with either compound was started at the day of CIA induction. Although FR104 previously demonstrated a higher control of T cell responses in vitro than abatacept, both compounds were equally potent in the suppression of CIA symptoms and biomarkers, such as the production of C-reactive protein (CRP) and interleukin (IL)-6 and anti-collagen type II (CII) serum antibody (IgM/IgG). However, in contrast to abatacept, FR104 showed effective suppression of CII-induced peripheral blood mononuclear cell (PBMC) proliferation. The current study demonstrates a strong potential of the new selective CD28 antagonist FR104 for treatment of RA.

Cytomegalovirus-Neutralizing Antibody Responses are Associated With Protection Against Fetal Loss, but Not Placental Transmission, in a Novel Rhesus Monkey Model of Congenital CMV Transmission

Cytomegalovirus-Neutralizing Antibody Responses are Associated With Protection Against Fetal Loss, but Not Placental Transmission, in a Novel Rhesus Monkey Model of Congenital CMV Transmission

Anti-inflammatory effects of dexamethasone and meloxicam on Borrelia burgdorferi-induced inflammation in neuronal cultures of dorsal root ganglia and myelinating cells of the peripheral nervous system.

BackgroundLyme neuroborreliosis (LNB), caused by the spirochete Borrelia burgdorferi (Bb), could result in cognitive impairment, motor dysfunction, and radiculoneuritis. We hypothesized that inflammation is a key factor in LNB pathogenesis and recently evaluated the effects of dexamethasone, a steroidal anti-inflammatory drug, and meloxicam a non-steroidal anti-inflammatory drug (NSAID), in a rhesus monkey model of acute LNB. Dexamethasone treatment significantly reduced the levels of immune mediators, and prevented inflammatory and/or neurodegenerative lesions in the central and peripheral nervous systems, and apoptosis in the dorsal root ganglia (DRG). However, infected animals treated with meloxicam showed levels of inflammatory mediators, inflammatory lesions, and DRG cell apoptosis that were similar to that of the infected animals that were left untreated.MethodsTo address the differential anti-inflammatory effects of dexamethasone and meloxicam on neuronal and myelinating cells of the peripheral nervous system (PNS), we evaluated the potential of these drugs to alter the levels of Bb-induced inflammatory mediators in rhesus DRG cell cultures and primary human Schwann cells (HSC), using multiplex enzyme-linked immunosorbent assays (ELISA). We also ascertained the ability of these drugs to modulate cell death as induced by live Bb in HSC using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) viability assay and the potential of dexamethasone to modulate Bb-induced apoptosis in HSC by the TUNEL assay.ResultsEarlier, we reported that dexamethasone significantly reduced Bb-induced immune mediators and apoptosis in rhesus DRG cell cultures. Here, we report that dexamethasone but not meloxicam significantly reduces the levels of several cytokines and chemokines as induced by live Bb, in HSC and DRG cell cultures. Further, meloxicam does not significantly alter Bb-induced cell death in HSC, while dexamethasone protects HSC against Bb-induced cell death.ConclusionsThese data help further explain our in vivo findings of significantly reduced levels of inflammatory mediators, DRG-apoptosis, and lack of inflammatory neurodegenerative lesions in the nerve roots and DRG of Bb-infected animals that were treated with dexamethasone, but not meloxicam. Evaluating the role of the signaling mechanisms that contribute to the anti-inflammatory potential of dexamethasone in the context of LNB could serve to identify therapeutic targets for limiting radiculitis and axonal degeneration in peripheral LNB.

Next-Generation mRNA Sequencing Reveals Pyroptosis-Induced CD4+ T Cell Death in Early Simian Immunodeficiency Virus-Infected Lymphoid Tissues.

Lymphoid tissues (LTs) are the principal sites where human immunodeficiency virus type 1 (HIV-1) replicates and virus-host interactions take place, resulting in immunopathology in the form of inflammation, immune activation, and CD4(+) T cell death. The HIV-1 pathogenesis in LTs has been extensively studied; however, our understanding of the virus-host interactions in the very early stages of infection remains incomplete. We investigated virus-host interactions in the rectal draining lymph nodes (dLNs) of rhesus macaques at different times after intrarectal inoculation (days postinoculation [dpi]) with simian immunodeficiency virus (SIV). At 3 dpi, 103 differentially expressed genes (DEGs) were detected using next-generation mRNA sequencing (RNA-seq). At 6 and 10 dpi, concomitant with increased SIV replication, 366 and 1,350 DEGs were detected, respectively, including upregulation of genes encoding proteins that play a role in innate antiviral immune responses, inflammation, and immune activation. Notably, genes (IFI16, caspase-1, and interleukin 1β [IL-1β]) in the canonical pyroptosis pathway were significantly upregulated in expression. We further validated increased pyroptosis using flow cytometry and found that the number of CD4(+) T cells expressing activated caspase-1 protein, the hallmark of ongoing pyroptosis, were significantly increased, which is correlated with decreased CD4(+) T cells in dLNs. Our results demonstrated that pyroptosis contributes to the CD4(+) T cell death in vivo in early SIV infection, which suggests that pyroptosis may play a pivotal role in the pathogenesis of SIV, and by extension, that of HIV-1, since pyroptosis not only induces CD4(+) T cell death but also amplifies inflammation and immune activation. Thus, blocking CD4(+) T cell pyroptosis could be a complementary treatment to antiretroviral therapy. Although secondary lymphoid tissues (LTs) are principal sites of human immunodeficiency virus type 1 (HIV-1) replication, inflammation, immune activation, and CD4(+) T cell death, immunopathogenesis in LTs during early infection remains largely unknown. Using the simian immunodeficiency virus (SIV)/rhesus monkey model of HIV rectal infection, we investigated early virus-host interactions. Our results revealed elevated potent host responses in early infection in LTs, including upregulation of genes involved in antiviral immune response, inflammation, and immune activation. Importantly, genes involved in the canonical pyroptosis pathway were significantly upregulated, and there was a strong correlation between CD4(+) T cell decrease and increased number of CD4(+) T cells expressing activated caspase-1 protein, demonstrating that pyroptosis contributes to CD4(+) T cell death in vivo in very early SIV infection. Our finding suggests that blocking pyroptosis may be able to decrease CD4(+) T cell loss during early SIV infection.

Tissue Distribution of Memory T and B Cells in Rhesus Monkeys following Influenza A Infection.

Studies of influenza-specific immune responses in humans have largely assessed systemic responses involving serum Ab and peripheral blood T cell responses. However, recent evidence indicates that tissue-resident memory T (TRM) cells play an important role in local murine intrapulmonary immunity. Rhesus monkeys were pulmonary exposed to 2009 pandemic H1N1 virus at days 0 and 28 and immune responses in different tissue compartments were measured. All animals were asymptomatic postinfection. Although only minimal memory immune responses were detected in peripheral blood, a high frequency of influenza nucleoprotein-specific memory T cells was detected in the lung at the "contraction phase," 49-58 d after second virus inoculation. A substantial proportion of lung nucleoprotein-specific memory CD8(+) T cells expressed CD103 and CD69, phenotypic markers of TRM cells. Lung CD103(+) and CD103(-) memory CD8(+) T cells expressed similar levels of IFN-γ and IL-2. Unlike memory T cells, spontaneous Ab secreting cells and memory B cells specific to influenza hemagglutinin were primarily observed in the mediastinal lymph nodes. Little difference in systemic and local immune responses against influenza was observed between young adult (6-8 y) and old animals (18-28 y). Using a nonhuman primate model, we revealed substantial induction of local T and B cell responses following 2009 pandemic H1N1 infection. Our study identified a subset of influenza-specific lung memory T cells characterized as TRM cells in rhesus monkeys. The rhesus monkey model may be useful to explore the role of TRM cells in local tissue protective immunity after rechallenge and vaccination.

Multiple Anesthetic Exposure in Infant Monkeys Alters Emotional Reactivity to an Acute Stressor

Retrospective studies in humans have shown a higher prevalence of learning disabilities in children that received multiple exposures to general anesthesia before the age of 4 yr. Animal studies, primarily in rodents, have found that postnatal anesthetic exposure causes neurotoxicity and neurocognitive deficits in adulthood. The authors addressed the question of whether repeated postnatal anesthetic exposure was sufficient to cause long-term behavioral changes in a highly translationally relevant rhesus monkey model, allowing study of these variables against a background of protracted nervous system and behavioral development. Rhesus monkeys of both sexes underwent either three 4-h exposures to sevoflurane anesthesia (anesthesia group n = 10) or brief maternal separations (control group n = 10) on postnatal day 6 to 10 that were repeated 14 and 28 days later. Monkeys remained with their mothers in large social groups at all times except for overnight observation after each anesthetic/control procedure. At 6 months of age, each monkey was tested on the human intruder paradigm, a common test for emotional reactivity in nonhuman primates. The frequency of anxiety-related behaviors was significantly higher in monkeys that were exposed to anesthesia as neonates as compared with controls: anesthesia 11.04 ± 1.68, controls 4.79 ± 0.77, mean ± SEM across all stimulus conditions. Increased emotional behavior in monkeys after anesthesia exposure in infancy may reflect long-term adverse effects of anesthesia.

Rhesus monkey model of liver disease reflecting clinical disease progression and hepatic gene expression analysis.

Alcoholic liver disease (ALD) is a significant public health issue with heavy medical and economic burdens. The aetiology of ALD is not yet completely understood. The development of drugs and therapies for ALD is hampered by a lack of suitable animal models that replicate both the histological and metabolic features of human ALD. Here, we characterize a rhesus monkey model of alcohol-induced liver steatosis and hepatic fibrosis that is compatible with the clinical progression of the biochemistry and pathology in humans with ALD. Microarray analysis of hepatic gene expression was conducted to identify potential molecular signatures of ALD progression. The up-regulation of expression of hepatic genes related to liver steatosis (CPT1A, FASN, LEPR, RXRA, IGFBP1, PPARGC1A and SLC2A4) was detected in our rhesus model, as was the down-regulation of such genes (CYP7A1, HMGCR, GCK and PNPLA3) and the up-regulation of expression of hepatic genes related to liver cancer (E2F1, OPCML, FZD7, IGFBP1 and LEF1). Our results demonstrate that this ALD model reflects the clinical disease progression and hepatic gene expression observed in humans. These findings will be useful for increasing the understanding of ALD pathogenesis and will benefit the development of new therapeutic procedures and pharmacological reagents for treating ALD.

GW26-e4756 Decreased Copper Concentrations But Increased Lysyl Oxidase in Rhesus Monkey Model of Myocardial Ischemic Infarction

GW26-e4756 Decreased Copper Concentrations But Increased Lysyl Oxidase in Rhesus Monkey Model of Myocardial Ischemic Infarction

Developmental consequences of behavioral inhibition: a model in rhesus monkeys (Macaca mulatta).

In children, behavioral inhibition is characterized by a disposition to withdraw in the presence of strangers and novel situations. Later in life, behavioral inhibition can result in an increased risk for anxiety and depression and a decrease in social behavior. We selected rhesus monkeys that, during infancy, showed evidence of behavioral inhibition in response to separation, and contrasted them with non-inhibited peers. To understand the development of behavioral inhibition at juvenile age, we collected behavioral data in response to relocation; in response to a human intruder challenge; and in naturalistic outdoor field corrals. At 4 years of age (young adulthood), we again collected behavioral data in the outdoor field corrals to understand the adult social consequences of behavioral inhibition. We also included sex, dominance rank, and number of available kin in our analyses. Finally, to understand the consistency in behavior in behaviorally inhibited animals, we conducted exploratory analyses contrasting behaviorally inhibited animals that showed high vs. low durations of non-social behaviors as adults. At juvenile age, behaviorally inhibited animals continued to show behavioral differences in the novel testing room and during the human intruder challenge, generally showing evidence of greater anxiety and emotionality compared to non-inhibited controls. In their outdoor corrals, behaviorally inhibited juveniles spent more time alone and less time in proximity and grooming with mother and other adult females. In young adulthood, we found that behavioral inhibition was not related to time spent alone. We did find that duration of time alone in adulthood was related to time alone exhibited as juveniles; sex, dominance rank, or the number of kin were not influential in adult non-social duration, either as main effects or as moderators. Finally, exploratory analyses revealed that behaviorally inhibited females that were more sociable (less time spent alone) as adults had spent more time grooming as juveniles, suggesting that high-quality social interaction at a young age might mitigate the social consequences of behavioral inhibition. Overall, we believe that the many similarities with the human data that we found suggest that this monkey model of naturally occurring behavioral inhibition can be valuable for understanding social development.

Immunodeficiency viruses and prion disease

Abstract. Two threatening human diseases have emerged during the past 35 years. Human immunodeficiency virus (HIV) was transmitted from non-human primates – e.g., the chimpanzee to humans – and then spread into populations all over the world. To date, around 35 million people are infected and no vaccine is available because the virus undergoes rapid mutation, resulting in a swarm of virus strains. At best, therapeutical intervention is possible with antiviral drugs; however because of its capacity to rapidly mutate, resistant virus strains develop. Since non-human primates (NHPs) carry simian immunodeficiency virus (SIV), we could assess infection and immunity by SIV/HIV in rhesus monkeys (M. mulatta) as a model for acquired immunodeficiency syndrome (AIDS). Transmissible spongiform encephalopathy (TSE) emerged in ruminants in the 1980s and shortly thereafter appeared in humans, leading to variant Creutzfeldt–Jakob disease (vCJD). The vCJD is a terminal neurological disorder since it heavily and irreversibly damages the brain. No cure is at hand. The causative agents for TSE are prions. They are unusual pathogens and enigmatic since they lack nucleic acid as inheritable information. On the other hand, prions were suspected as infectious agents for years and suspected to be the etiological agent of scrapie in sheep. Molecular biology and medicine have clearly identified prions in recent years as the responsible agent for bovine spongiform encephalopathy in ruminants (BSE). BSE has been transmitted to humans, resulting in around 225 vCJD cases. Similar to the SIV/HIV model for Acquired Immunodeficiency Syndrome (AIDS), we could establish a prion infection model in rhesus monkeys. HIV/AIDS and vCJD are zoonoses since their original pathogens can be transmitted from animals to humans. Our experimental efforts to understand these intriguing pathogens and their corresponding diseases in rhesus monkeys as a valid model for both human diseases are summarized in this review.

Plasma diacylglycerol composition is a biomarker of metabolic syndrome onset in rhesus monkeys

Metabolic syndrome is linked with obesity and is often first identified clinically by elevated BMI and elevated levels of fasting blood glucose that are generally secondary to insulin resistance. Using the highly translatable rhesus monkey (Macaca mulatta) model, we asked if metabolic syndrome risk could be identified earlier. The study involved 16 overweight but healthy, euglycemic monkeys, one-half of which spontaneously developed metabolic syndrome over the course of 2 years while the other half remained healthy. We conducted a series of biometric and plasma measures focusing on adiposity, lipid metabolism, and adipose tissue-derived hormones, which led to a diagnosis of metabolic syndrome in the insulin-resistant animals. Plasma fatty acid composition was determined by gas chromatography for cholesteryl ester, FFA, diacylglycerol (DAG), phospholipid, and triacylglycerol lipid classes; plasma lipoprotein profiles were generated by NMR; and circulating levels of adipose-derived signaling peptides were determined by ELISA. We identified biomarker models including a DAG model, two lipoprotein models, and a multiterm model that includes the adipose-derived peptide adiponectin. Correlations among circulating lipids and lipoproteins revealed shifts in lipid metabolism during disease development. We propose that lipid profiling may be valuable for early metabolic syndrome detection in a clinical setting.

Discovery of novel triazolobenzazepinones as γ-secretase modulators with central Aβ42 lowering in rodents and rhesus monkeys

Synthesis and SAR studies of novel triazolobenzazepinones as gamma secretase modulators (GSMs) are presented in this communication. Starting from our azepinone leads, optimization studies toward improving central lowering of Aβ42 led to the discovery of novel benzo-fused azepinones. Several benzazepinones were profiled in vivo and found to lower brain Aβ42 levels in Sprague Dawley rats and transgenic APP-YAC mice in a dose-dependent manner after a single oral dose. Compound 34 was further progressed into a pilot study in our cisterna-magna-ported rhesus monkey model, where we observed robust lowering of CSF Aβ42 levels.