Demyelination and remyelination play key roles in spinal cord injury (SCI), affecting the recovery of motor and sensory functions. Research in rodent models is extensive, but the study of these processes in non-human primates is limited. Therefore, our goal was to thoroughly study the histological features of demyelination and remyelination after contusion injury of the cervical spinal cord in Macaca fascicularis. In a previous study, we created an SCI model in M. fascicularis by controlling the contusion displacement. We used Eriochrome Cyanine staining, immunohistochemical analysis, and toluidine blue staining to evaluate demyelination and remyelination. The results showed demyelination ipsilateral to the injury epicenter both rostrally and caudally, the former mainly impacting sensory pathways, while the latter primarily affected motor pathways. Toluidine blue staining showed myelin loss and axonal distension at the injury site. Schwann cell-derived myelin sheaths were only found at the center, while thinner myelin sheaths from oligodendrocytes were seen at the center and surrounding areas. Our study showed that long-lasting demyelination occurs in the spinal cord of M. fascicularis after SCI, with oligodendrocytes and Schwann cells playing a significant role in myelin sheath formation at the injury site.
Animals ; Spinal Cord Injuries/physiopathology* ; Demyelinating Diseases/etiology* ; Remyelination/physiology* ; Macaca fascicularis ; Disease Models, Animal ; Myelin Sheath/pathology* ; Oligodendroglia/pathology* ; Schwann Cells/pathology* ; Female ; Spinal Cord/pathology* ; Axons/pathology*

Complex brain diseases seriously endanger human health, and early diagnostic biomarkers and effective treatments are currently lacking. Due to ethical constraints on human research, establishing monkey models is crucial to address these issues. With the rapid development of technology, transgenic monkey models of a range of brain diseases, especially autism spectrum disorder (ASD), have been successfully established. However, to establish practical and effective brain disease models and subsequently apply them to disease mechanism and treatment studies, there is still a lack of a standard tool, i.e., a system for collecting and analyzing the daily behaviors of brain disease model monkeys. Therefore, with the goal of undertaking a comprehensive and quantitative study of behavioral phenotypes, we established a standard daily behavior collection and analysis system, including behavioral data collection protocols and a monkey daily behavior ethogram (MDBE) for rhesus and cynomolgus monkeys, which are the most commonly used non-human primates in model construction. Then, we used ASD as an application example after referring to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), which is widely used in clinical disease diagnosis to obtain ASD core clinical symptoms. We then established a sub-ethogram (ASD monkey core behavior ethogram (MCBE-ASD)) specifically for quantitative assessment of the core clinical symptoms of an ASD monkey model based on MDBE. Subsequently, we demonstrated the high reproducibility of the system.
Animals ; Autism Spectrum Disorder ; Macaca mulatta ; Disease Models, Animal ; Behavior, Animal ; Macaca fascicularis ; Male ; Humans

OBJECTIVE: To investigate the feasibility of establishing an anterior cruciate ligament (ACL) reconstruction model using hamstring tendon autograft in cynomolgus monkeys. METHODS: Twelve healthy adult male cynomolgus monkeys, weighing 8-13 kg, were randomly divided into two groups ( n=6). In the experimental group, the ACL reconstruction model of the right lower limb was prepared by using a single bundle of hamstring tendon, and the ACL of the right lower limb was only cut off in the control group. The survival of animals in the two groups was observed after operation. Before operation and at 3, 6, and 12 months after operation, the knee range of motion, thigh circumference, and calf circumference of the two groups were measured; the anterior tibial translation D-value (ATTD) was measured by Ligs joint ligament digital body examination instrument under the loads of 13-20 N, respectively. At the same time, the experimental group underwent MRI examination to observe the graft morphology and the signal/ noise quotient (SNQ) was caculated. RESULTS: All animals survived to the end of the experiment. In the experimental group, the knee range of motion, thigh circumference, and calf circumference decreased first and then gradually increased after operation; the above indexes were significantly lower at 3 and 6 months after operation than before operation ( P<0.05), and no significant difference was found between pre-operation and 12 months after operation ( P>0.05). In the control group, there was no significant change in knee range of motion after operation, showing no significant difference between pre- and post-operation ( P>0.05), but the thigh circumference and calf circumference gradually significantly decreased with time ( P<0.05), and the difference was significant when compared with those before operation ( P<0.05). At 6 and 12 months after operation, the thigh circumference and calf circumference were significantly larger in the experimental group than in the control group ( P<0.05). At 3 and 6 months after operation, the knee range of motion was significantly smaller in the experimental group than in the control group ( P<0.05). Under the loading condition of 13-20 N, the ATTD in the experimental group increased first and then decreased after operation; and the ATTD significantly increased at 3, 6 months after operation when compared with the value before operation ( P<0.05). But there was no significant difference between the pre-operation and 12 months after operation ( P>0.05). There was no significant change in ATTD in the control group at 3, 6, and 12 months after operation ( P>0.05), and which were significantly higher than those before operation ( P<0.05). At each time point after operation, the ATTD was significantly smaller in the experimental group than in the control group under the same load ( P<0.05). The MRI examination of the experimental group showed that the ACL boundary gradually became clear after reconstruction and was covered by the synovial membrane. The SNQ at each time point after operation was significantly higher than that before operation, but gradually decreased with time, and the differences between time points were significant ( P<0.05). CONCLUSION The ACL reconstruction model in cynomolgus monkey with autogenous hamstring tendon transplantation was successfully established.
Animals ; Male ; Anterior Cruciate Ligament/surgery* ; Anterior Cruciate Ligament Injuries/surgery* ; Anterior Cruciate Ligament Reconstruction ; Hamstring Tendons/surgery* ; Knee Joint/surgery* ; Macaca fascicularis ; Transplantation, Autologous

Aging poses a major risk factor for cardiovascular diseases, the leading cause of death in the aged population. However, the cell type-specific changes underlying cardiac aging are far from being clear. Here, we performed single-nucleus RNA-sequencing analysis of left ventricles from young and aged cynomolgus monkeys to define cell composition changes and transcriptomic alterations across different cell types associated with age. We found that aged cardiomyocytes underwent a dramatic loss in cell numbers and profound fluctuations in transcriptional profiles. Via transcription regulatory network analysis, we identified FOXP1, a core transcription factor in organ development, as a key downregulated factor in aged cardiomyocytes, concomitant with the dysregulation of FOXP1 target genes associated with heart function and cardiac diseases. Consistently, the deficiency of FOXP1 led to hypertrophic and senescent phenotypes in human embryonic stem cell-derived cardiomyocytes. Altogether, our findings depict the cellular and molecular landscape of ventricular aging at the single-cell resolution, and identify drivers for primate cardiac aging and potential targets for intervention against cardiac aging and associated diseases.
Aged ; Animals ; Humans ; Aging/genetics* ; Forkhead Transcription Factors/metabolism* ; Myocytes, Cardiac/metabolism* ; Primates/metabolism* ; Repressor Proteins/metabolism* ; Transcriptome ; Macaca fascicularis/metabolism*

Animals ; Monkeypox/drug therapy* ; Antiviral Agents/therapeutic use* ; Phosphoric Monoester Hydrolases/therapeutic use* ; Macaca fascicularis

Aging/metabolism* ; Animals ; Gene Expression Regulation ; Macaca fascicularis ; Retina/metabolism* ; Single-Cell Analysis

Many human genetic diseases, including Hutchinson-Gilford progeria syndrome (HGPS), are caused by single point mutations. HGPS is a rare disorder that causes premature aging and is usually caused by a de novo point mutation in the LMNA gene. Base editors (BEs) composed of a cytidine deaminase fused to CRISPR/Cas9 nickase are highly efficient at inducing C to T base conversions in a programmable manner and can be used to generate animal disease models with single amino-acid substitutions. Here, we generated the first HGPS monkey model by delivering a BE mRNA and guide RNA (gRNA) targeting the LMNA gene via microinjection into monkey zygotes. Five out of six newborn monkeys carried the mutation specifically at the target site. HGPS monkeys expressed the toxic form of lamin A, progerin, and recapitulated the typical HGPS phenotypes including growth retardation, bone alterations, and vascular abnormalities. Thus, this monkey model genetically and clinically mimics HGPS in humans, demonstrating that the BE system can efficiently and accurately generate patient-specific disease models in non-human primates.
Animals ; Disease Models, Animal ; Female ; Gene Editing ; Humans ; Lamin Type A/metabolism* ; Macaca fascicularis ; Progeria/pathology*

Microorganisms play important roles in obesity; however, the role of the gut microbiomes in obesity is controversial because of the inconsistent findings. This study investigated the gut microbiome communities in obese and lean groups of captive healthy cynomolgus monkeys reared under strict identical environmental conditions, including their diet. No significant differences in the relative abundance of Firmicutes, Bacteroidetes and Prevotella were observed between the obese and lean groups, but a significant difference in Spirochetes (p < 0.05) was noted. Microbial diversity and richness were similar, but highly variable results in microbial composition, diversity, and richness were observed in individuals, irrespective of their state of obesity. Distinct clustering between the groups was not observed by principal coordinate analysis using an unweighted pair group method. Higher sharedness values (95.81% ± 2.28% at the genus level, and 79.54% ± 5.88% at the species level) were identified among individual monkeys. This paper reports the association between the gut microbiome and obesity in captive non-human primate models reared under controlled environments. The relative proportion of Firmicutes and Bacteroidetes as well as the microbial diversity known to affect obesity were similar in the obese and lean groups of monkeys reared under identical conditions. Therefore, obesity-associated microbial changes reported previously appear to be associated directly with environmental factors, particularly diet, rather than obesity.
Bacteroidetes ; Diet ; Environment, Controlled ; Firmicutes ; Gastrointestinal Microbiome ; Haplorhini ; Macaca fascicularis ; Methods ; Microbiota ; Obesity ; Prevotella ; Primates ; Spirochaetales

Animals ; Antibodies, Monoclonal ; pharmacokinetics ; therapeutic use ; Antibodies, Viral ; therapeutic use ; Hepatitis B virus ; immunology ; Histocompatibility Antigens Class I ; metabolism ; Humans ; Macaca fascicularis ; Mice ; Protein Binding ; Protein Engineering ; Receptors, Fc ; metabolism

PURPOSE: Recent studies investigating new strategies to modulate the immune system have utilized animal models of liver transplantation (LT). However, the anhepatic phase (AHP) remains a crucial problem in LT. The aim of the present study is to introduce a technique for successful orthotopic LT in cynomolgus monkeys using an early-reperfusion strategy. METHODS: Orthotopicallo-LT was performed with seven donor/recipient pairs of cynomolgus monkeys. RESULTS: In 2 recipients, liver allografts were perfused after suprahepatic inferior vena cava (SHIVC), portal vein (PV), and infrahepatic inferior vena cava (IHIVC) anastomosis. To reduce the time of AHP in five recipients, liver allografts ware perfused after SHIVC and PV anastomosis while the IHIVC was not anastomosed. In the latter strategy, the AHP was reduced from 46 minutes to 31 minutes and a 24-hour survival rate of 80% was achieved. CONCLUSION: Our results indicate that an early-reperfusion strategy can be successfully used to establish a LT model in cynomolgus monkeys with a consistently high rate of animal survival.
Allografts ; Animals ; Immune System ; Liver Transplantation ; Liver ; Macaca fascicularis ; Models, Animal ; Portal Vein ; Primates ; Reperfusion ; Survival Rate ; Vena Cava, Inferior