Nonhuman primate models of focal cerebral ischemia

Rodents have been widely used in the production of cerebral ischemia models. However, successful therapies have been proven on experimental rodent stroke model, and they have often failed to be effective when tested clinically. Therefore, nonhuman primates were recommended as the ideal alternatives, owing to their similarities with the human cerebrovascular system, brain metabolism, grey to white matter ratio and even their rich behavioral repertoire. The present review is a thorough summary of ten methods that establish nonhuman primate models of focal cerebral ischemia; electrocoagulation, endothelin-1-induced occlusion, microvascular clip occlusion, autologous blood clot embolization, balloon inflation, microcatheter embolization, coil embolization, surgical suture embolization, suture, and photochemical induction methods. This review addresses the advantages and disadvantages of each method, as well as precautions for each model, compared nonhuman primates with rodents, different species of nonhuman primates and different modeling methods. Finally it discusses various factors that need to be considered when modelling and the method of evaluation after modelling. These are critical for understanding their respective strengths and weaknesses and underlie the selection of the optimum model.

Endovascular middle cerebral arterial occlusion in a nonhuman primate model of chronic stroke

No study has reported the safety, effectiveness, and consistency of endovascular middle cerebral artery occlusion in a chronic cerebral ischemia model. Nor have studies verified the safest and most effective segment, or branch, in the embolic middle cerebral artery. In this experiment, cerebral infarction models were established at M1, and on the upper and lower trunks on the contralateral side of the handedness of rhesus monkeys by using endovascular intervention. The results confirmed a high animal survival rate in stroke models of middle cerebral artery upper trunk occlusion. There was pronounced paralysis at the acute phase, long-term upper extremity dysfunction at the chronic phase, and the models showed good repeatability and consistency. Thus, this study describes a safe and effective model of chronic stroke.

Comparative evaluation of acute phase proteins by C-reactive protein(CRP)and serum amyloid A(SAA)in nonhuman primates and feline carnivores

The feasibility of a commercially available assay for C-reactive protein(CRP,CRP for humans:hCRP,and CRP for dogs:vCRP)and a trial reagent of serum amyloid A(SAA,vSAA for animals)were applied to the measurement of acute phase proteins in zoo animals,particularly in nonhuman primates and feline carnivores was evaluate.Results showed that hCRP and vSAA methods were applicable to measure CRP and SAA in Haplorhini.There was a highly signifcant correlation between both parameters with remarkably high correlation coefcient.A higher proportion of Bonnet macaques in Haplorhini,and the linear regression with good correlation between hCRP and vSAA levels were observed.Reference values in healthy Bonnet macaques were hCRP(46.86±30.97 nmol/L)and vSAA(9.06±1.95μg/mL).Although Ring-tailed lemur,which belonging to Strepsirrhini,showed low vSAA concentrations(reference values:1.08±0.47μg/mL),vSAA in patients was apparently elevated.The vCRP and vSAA methods were applicable to measurements of CRP and SAA in feline carnivores for highly signifcant correlation between both parameters.Theses two methods were also been deteded in lions,tigers and cheetahs.vSAA assays can be applied to measure SAA levels in other carnivores and herbivores.In conclusion,vSAA systems have potential utility as diagnostic tools for health screening and prediction in zoo animals.

Transgenic Nonhuman Primate Models for Human Diseases:Approaches and Contributing Factors

Nonhuman primates （NHPs） provide powerful experimental models to study human development, cognitive functions and disturbances as well as complex behavior, because of their genetic and physiological similarities to humans. Therefore, NHPs are appropriate models for the study of human diseases, such as neurodegenerative diseases including Parkinson＇s, Alzheimer＇s and Huntington＇s diseases, which occur as a result of genetic mutations. However, such diseases afflicting humans do not occur naturally in NHPs. So transgenic NHPs need to be established to understand the etiology of disease pathology and pathogenesis. Compared to rodent genetic models, the generation of transgenic NHPs for human diseases is inefficient, and only a transgenic monkey model for Huntington＇s disease has been reported. This review focuses on potential approaches and contributing factors for generating transgenic NHPs to study human diseases.

Assessing the nonhuman primate reservoir of Schistosoma mansoni in Africa:a systematic review

Background:Reports of natural infections of Schistosoma mansoni in a number of species of nonhuman primates(NHPs)in Africa,coupled with the substantial overlap of NHP habitats and human schistosomiasis endemic areas,has led to concerns about the role of NHPs in the transmission of human schistosomiasis.We conducted a systematic review of the literature to describe the current scope of knowledge for Africa,for the NHP species implicated,their geographical distribution,infection rates with 5.mansoni,and to discuss the implications for public health and conservation.Main text:A systematic search of the literature was performed using PubMed,Web of Science,Google Scholar,the World Health Organization(WHO)library database,World Cat,and ScienceDirect without any language restriction.Studies examining 5.monsoni infeaion of any African NHP species were included.Study types,primate species,their geographical distribution,and parasite diagnostic techniques reported in the studies were qualitatively summarized.Data for species with sample sizes>10 were included in the meta-analysis.We assessed the reported infection rate,and used a random-effeas model to estimate the summary infeaion rates and 95%confidence intervals(C/s).We assessed heterogeneity among studies using the I2 statistics.Twenty-nine publications,from 1960 to 2018,were identified and included in the review.The studies examined a total of 2962 primates belonging to 22 species in 11 genera across ten countries(Cameroon,Eritrea,Ethiopia,Gabon,Kenya,Nigeria,Senegal,Tanzania,Uganda,and Zimbabwe),and 5.mansoni infeaions were found in nine species of five genera in all countries.When we excluded studies with sample sizes<10,data from 24 studies on 11 species of primates in three genera in ten countries remained in the meta-analysis.The overall pooled estimate of infection rate was 10%(95%Cl:6-16%)with high heterogeneity(I^2=9477%)across countries and species/genera.Among the three genera,Pan had the highest infection rate of 15%(95%CI:0-55%),followed by Popio at 11%(95%Cl:6-18%),and Cercopithecus at 5%(95%CI:0-14%).The association between NHP and human infections was positive,but not significant,due to low study sample matches and high variation.Conclusions:Our findings suggest that 5.mansoni infection rate is high in African NHPs,with substantial heterogeneities across spedes/genera and countries in Africa.Given the evidence for potential spillover and spillback of S.mansoni between African NHPs and humans,further research is urgently needed to understand ecology and mechanisms of transmission of the parasite between NHP and human hosts,in order to inform control strategies of this important neglected tropical disease.

Comparative transcriptome analysis between rhesus macaques(Macaca mulatta) and crab-eating macaques(M. fascicularis)

Understanding gene expression variations between species is pivotal for deciphering the evolutionary diversity in phenotypes. Rhesus macaques(Macaca mulatta, MMU)and crab-eating macaques(M. fascicularis, MFA) serve as crucial nonhuman primate biomedical models with different phenotypes. To date, however, large-scale comparative transcriptome research between these two species has not yet been fully explored. Here, we conducted systematic comparisons utilizing newly sequenced RNA-seq data from84 samples(41 MFA samples and 43 MMU samples)encompassing 14 common tissues. Our findings revealed a small fraction of genes(3.7%) with differential expression between the two species, as well as 36.5% of genes with tissue-specific expression in both macaques. Comparison of gene expression between macaques and humans indicated that 22.6% of orthologous genes displayed differential expression in at least two tissues. Moreover,19.41% of genes that overlapped with macaque-specific structural variants showed differential expression between humans and macaques. Of these, the FAM220A gene exhibited elevated expression in humans compared to macaques due to lineage-specific duplication. In summary,this study presents a large-scale transcriptomic comparison between MMU and MFA and between macaques and humans. The discovery of gene expression variations not only enhances the biomedical utility of macaque models but also contributes to the wider field of primate genomics.

Disease modifying treatment of spinal cord injury with directly reprogrammed neural precursor cells in non-human primates

BACKGROUND The development of regenerative therapy for human spinal cord injury(SCI)is dramatically restricted by two main challenges:the need for a safe source of functionally active and reproducible neural stem cells and the need of adequate animal models for preclinical testing.Direct reprogramming of somatic cells into neuronal and glial precursors might be a promising solution to the first challenge.The use of non-human primates for preclinical studies exploring new treatment paradigms in SCI results in data with more translational relevance to human SCI.AIM To investigate the safety and efficacy of intraspinal transplantation of directly reprogrammed neural precursor cells(drNPCs).METHODS Seven non-human primates with verified complete thoracic SCI were divided into two groups:drNPC group(n=4)was subjected to intraspinal transplantation of 5 million drNPCs rostral and caudal to the lesion site 2 wk post injury,and lesion control(n=3)was injected identically with the equivalent volume of vehicle.RESULTS Follow-up for 12 wk revealed that animals in the drNPC group demonstrated a significant recovery of the paralyzed hindlimb as well as recovery of somatosensory evoked potential and motor evoked potential of injured pathways.Magnetic resonance diffusion tensor imaging data confirmed the intraspinal transplantation of drNPCs did not adversely affect the morphology of the central nervous system or cerebrospinal fluid circulation.Subsequent immunohistochemical analysis showed that drNPCs maintained SOX2 expression characteristic of multipotency in the transplanted spinal cord for at least 12 wk,migrating to areas of axon growth cones.CONCLUSION Our data demonstrated that drNPC transplantation was safe and contributed to improvement of spinal cord function after acute SCI,based on neurological status assessment and neurophysiological recovery within 12 wk after transplantation.The functional improvement described was not associated with neuronal differentiation of the allogeneic drNPCs.Instead,directed drNPCs migration to the areas of active growth cone formation may provide exosome and paracrine trophic support,thereby further supporting the regeneration processes.

Development of a unilateral ureteral obstruction model in cynomolgus monkeys

Background:Chronic kidney disease(CKD)has a high global prevalence and large unmet need.Central to developing new CKD therapies are in vivo models in CKD.However,next-generation antibody,protein,and gene therapies are highly specific,meaning some do not cross-react with rodent targets.This complicates preclinical development,as established in vivo rodent models cannot be utilized unless tool therapeutics are also developed.Tool compounds can be difficult to develop and,if available,typically have different epitopes,sequences,and/or altered affinity,making it unclear how efficacious the lead therapeutic may be,or what dosing regimen to investigate.To address this,we aimed to develop a nonhuman primate model of CKD.Methods:In vivo rodent unilateral ureteral obstruction(UUO)models kidney fibrosis and is commonly used due to its rapidity,consistency,and ease.We describe translation of this model to the cynomolgus monkey,specifically optimizing the model duration to allow adequate time for assessment of novel therapeutics prior to the fibrotic plateau.Results:We demonstrated that disease developed more slowly in cynomolgus monkeys than in rodents post-UUO,with advanced fibrosis developing by 6 weeks.The tubulointerstitial fibrosis in cynomolgus monkeys was more consistent with human obstructive disease than in rodents,having a more aggressive tubular basement expansion and a higher fibroblast infiltration.The fibrosis was also associated with increased transglutaminase activity,consistent with that seen in patients with CKD.Conclusion:This cynomolgus monkey UUO model can be used to test potential human-specific therapeutics in kidney fibrosis.

利用CRISPR/Cas9技术在活体青年猕猴脑内进行基因编辑诱导其出现孤独症谱系障碍的行为表型

尽管CRISPR/Cas9基因编辑技术被广泛应用于人类疾病建模工作,但此前并无人利用该技术在非人灵长类脑内通过对疾病相关基因的编辑诱导出猕猴的行为表型.本研究利用AAV介导的CRISPR/Cas9技术,对活体猕猴海马脑区中与孤独症谱系障碍(ASD)和瑞特综合症(RTT)发病密切相关的MECP2基因进行编辑,基因编辑组猕猴(n=7)与其自身基因编辑前作为对照,同时与注射空载病毒的对照组猕猴(n=4)相比,其在基因编辑后出现了部分与孤独症临床症状十分相似的行为学改变,包括社交障碍、睡眠节律紊乱、对外界刺激的迟钝和手部精细运动受损等.可是另一些典型的孤独症症状,比如刻板运动,又没有在这些基因编辑猴中被观察到.以上现象提示不同的脑区在该疾病中可能扮演不同的角色.本研究利用上述技术能够快速高效地在猕猴上复制出相关疾病的症状,也为今后探索快速成模的转基因工程猕猴疾病模型奠定了基础.此类猕猴模型将为脑疾病的机理研究以及治疗作出重要贡献.

Discovery of a highly specific ^(18)F-labeled PET ligand for phosphodiesterase 10A enabled by novel spirocyclic iodonium ylide radiofluorination

As a member of cyclic nucleotide phosphodiesterase(PDE)enzyme family,PDE10A is in charge of the degradation of cyclic adenosine(cAMP)and guanosine monophosphates(cGMP).While PDE10A is primarily expressed in the medium spiny neurons of the striatum,it has been implicated in a variety of neurological disorders.Indeed,inhibition of PDE10A has proven to be of potential use for the treatment of central nervous system(CNS)pathologies caused by dysfunction of the basal ganglia–of which the striatum constitutes the largest component.A PDE10A-targeted positron emission tomography(PET)radioligand would enable a better assessment of the pathophysiologic role of PDE10A,as well as confirm the relationship between target occupancy and administrated dose of a given drug candidate,thus accelerating the development of effective PDE10A inhibitors.In this study,we designed and synthesized a novel ^(18)F-aryl PDE10A PET radioligand,codenamed[^(18)F]P10A-1910([^(18)F]9),in high radiochemical yield and molar activity via spirocyclic iodonium ylide-mediated radiofluorination.[^(18)F]9 possessed good in vitro binding affinity(IC_(50)=2.1 nmol/L)and selectivity towards PDE10A.Further,[^(18)F]9 exhibited reasonable lipophilicity(logD=3.50)and brain permeability(P_(app)>10×10^(−6) cm/s in MDCK-MDR1 cells).PET imaging studies of[^(18)F]9 revealed high striatal uptake and excellent in vivo specificity with reversible tracer kinetics.Preclinical studies in rodents revealed an improved plasma and brain stability of[^(18)F]9 when compared to the current reference standard for PDE10A-targeted PET,[^(18)F]MNI659.Further,dose–response experiments with a series of escalating doses of PDE10A inhibitor 1 in rhesus monkey brains confirmed the utility of[^(18)F]9 for evaluating target occupancy in vivo in higher species.In conclusion,our results indicated that[^(18)F]9 is a promising PDE10A PET radioligand for clinical translation.

The tale of autologous iPSCs:A monkey perspective

The breakthrough invention of induced pluripotent stem cells(iPSCs)ignited huge excitement with the promise of unlimited autologous cell sources for future regenerative medicine.1,2 However,before this expectation turns into reality the safety and efficacy of these autologous cell products have to be meticulously evaluated and validated.Towards this end much research effort has been concentrated on three clinically relevant aspects:tumorigenesis,immunogenesis,and efficacy.