AREAS COVERED: Herein, the authors discuss the various factors that contribute to the quality of studies using animal models based on the evaluation of studies published in 2022. The factors affecting the quality of studies using animal models, such as the animal species, age, and sex, are discussed, along with various methods and outcomes of studies involving different animal models of glaucoma.
EXPERT OPINION: Translating animal research data to clinical applications remains challenging. Our observations in this review clearly indicate that many studies lack scientific robustness not only in their experiment conduct but also in data analysis, interpretation, and presentation. In this context, ensuring the internal validity of animal studies is the first step in quality assurance. External validity, however, is more challenging, and steps should be taken to satisfy external validity at least to some extent.
METHODS: Thirty rabbits underwent either anterior cruciate ligament transection (ACLT) procedure or injected intraarticularly with monosodium iodoacetate (MIA, 8 mg) at the right knee joint. The subchondral bones were scanned via micro-CT, and articular cartilage was assessed histologically at 4-, 8- and 12-week post-induction.
RESULTS: Based on bone micro-architecture parameters, the surgically induced group revealed bone remodelling processes, indicated by increase bone volume, thickening of trabeculae, reduced trabecular separation and reduced porosity. On the other hand, the chemically induced group showed active bone resorption processes depicted by decrease bone volume, thinning of trabeculae, increased separation of trabecular and increased porosity consistently until week 12. Histologically, the chemically induced group showed more severe articular cartilage damage compared to the surgically induced group.
CONCLUSIONS: It can be concluded that in the ACLT group, subchondral bone remodelling precedes articular cartilage damage and vice versa in the MIA group. The findings revealed distinct pathogenic pathways for both induction methods, providing insight into tailored therapeutic strategies, as well as disease progression and treatment outcomes monitoring.
BACKGROUND: Cognitive impairments, altered emotional responsiveness, depression, and anxiety are the common neuropsychiatric co-morbidities observed in TLE patients. Mesenchymal stem cells (MSCs) transplantation has gained immense attention in treating TLE, as ~30% of patients do not respond to anti-epileptic drugs. While MSCs are known to cross the BBB, better CNS homing and therapeutic effects could be achieved when the systemic administration of MSC is timed with BBB damage following SE.
OBJECTIVES: The objectives of the present study are to investigate the effects of systemic administration of DPSCs/BM-MSCs timed with BBB damage on CNS homing of DPSCs/BM-MSCs, neurodegeneration, neuroinflammation and neuropsychiatric comorbidities in an animal model of TLE.
METHODOLOGY: We first assessed the BBB leakage following kainic acid-induced SE and timed the intravenous administration of DPSCs/BM-MSCs to understand the CNS homing/engraftment potential of DPSCs/BM-MSCs and their potential to mitigate neurodegeneration, neuroinflammation and neuropsychiatric comorbidities.
RESULTS: Our results revealed that systemic administration of DPSCs/BM-MSCs attenuated neurodegeneration, neuroinflammation, and ameliorated neuropsychiatric comorbidities. Three months following intravenous administration of DPSCs/BM-MSCs, we observed a negligible number of engrafted cells in the corpus callosum, sub-granular zone, and sub-ventricular zone.
CONCLUSION: Thus, it is evident that functional recovery is still achievable despite poor engraftment of MSCs into CNS following systemic administration.