Cerebral ischemia/reperfusion (I/R) injury is an important pathophysiological condition of ischemic stroke that involves a variety of physiological and pathological cell death pathways, including autophagy, apoptosis, necroptosis, and phagoptosis, among which autophagy is the most studied. We have reviewed studies published in the past 5 years regarding the association between autophagy and cerebral I/R injury. To the best of our knowledge, this is the first review article summarizing potential candidates targeting autophagic pathways in the treatment of I/R injury post ischemic stroke. The findings of this review may help to better understand the pathogenesis and mechanisms of I/R events and bridge the gap between basic and translational research that may lead to the development of novel therapeutic approaches for I/R injury.
Background: Although decompression surgery is the optimal treatment for patients with severe degenerative cervical myelopathy (DCM), some individuals experience no improvement or even a decline in neurological function after surgery, with spinal cord ischemia–reperfusion injury (SCII) identified as the primary cause. Spinal cord compression results in local ischemia and blood perfusion following decompression is fundamental to SCII. However, owing to inadequate perioperative blood flow monitoring, direct evidence regarding the occurrence of SCII after decompression is lacking. The objective of this study was to establish a suitable animal model for investigating the underlying mechanism of spinal cord ischemia–reperfusion injury following decompression surgery for degenerative cervical myelopathy (DCM) and to elucidate alterations in neurological function and local blood flow within the spinal cord before and after decompression.
Methods: Twenty-four Sprague–Dawley rats were allocated to three groups: the DCM group (cervical compression group, with implanted compression material in the spinal canal, n = 8), the DCM-D group (cervical decompression group, with removal of compression material from the spinal canal 4 weeks after implantation, n = 8), and the SHAM group (sham operation, n = 8). Von Frey test, forepaw grip strength, and gait were assessed within 4 weeks post-implantation. Spinal cord compression was evaluated using magnetic resonance imaging. Local blood flow in the spinal cord was monitored during the perioperative decompression. The rats were sacrificed 1 week after decompression to observe morphological changes in the compressed or decompressed segments of the spinal cord. Additionally, NeuN expression and the oxidative damage marker 8-oxoG DNA were analyzed.
Results: Following spinal cord compression, abnormal mechanical pain worsened, and a decrease in forepaw grip strength was observed within 1–4 weeks. Upon decompression, the abnormal mechanical pain subsided, and forepaw grip strength was restored; however, neither reached the level of the sham operation group. Decompression leads to an increase in the local blood flow, indicating improved perfusion of the spinal cord. The number of NeuN-positive cells in the spinal cord of rats in the DCM-D group exceeded that in the DCM group but remained lower than that in the SHAM group. Notably, a higher level of 8-oxoG DNA expression was observed, suggesting oxidative stress following spinal cord decompression.
Conclusion: This model is deemed suitable for analyzing the underlying mechanism of SCII following decompressive cervical laminectomy, as we posit that the obtained results are comparable to the clinical progression of degenerative cervical myelopathy (DCM) post-decompression and exhibit analogous neurological alterations. Notably, this model revealed ischemic reperfusion in the spinal cord after decompression, concomitant with oxidative damage, which plausibly underlies the neurological deterioration observed after decompression.
Background: The aim of the study was to explore a feasible method for alleviating limb ischemia–reperfusion injury (LI/RI) through the use of a high-concentration citrate solution (HC-A solution) for limb perfusion (LP).
Methods: Eighteen pigs were divided into three groups: the Sham group, LI/RI group, and HCA group. The Sham group underwent exposure of the iliac artery and vein. The LI/RI group underwent tourniquet placement and clamping of the iliac artery and vein to simulate LI/RI. The HCA group received HC-A solution LP for 30 min through the left iliac artery below the level of blood flow occlusion based on the LI/RI group. Oxidative stress markers and inflammatory response markers were compared among the three groups.
Results: Compared to the LI/RI group, the HCA group showed significantly lower levels of serum creatine kinase (CK), lactate dehydrogenase (LDH), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), aspartate aminotransferase (AST), and alanine aminotransferase (ALT), and significantly greater activities of serum superoxide dismutase (SOD) (p < 0.05). There were no significant differences in serum interleukin-6 (IL-6) or in muscle MDA, SOD, TNF-α, and IL-6 between the HCA group and the LI/RI group (p > 0.05). Compared to the LI/RI group, MDA, TNF-α, and IL-6 levels in the liver were significantly lower in the HCA group (p < 0.05), while SOD activities were not significantly different (p > 0.05). Histopathological examination revealed reduced skeletal muscle and liver damage in the HCA group compared to the LI/RI group.
Conclusions: HC-A solution LP can alleviate liver damage caused by LI/RI in pigs.
Glaucoma, a visual thief, is characterized by elevated intraocular pressure (IOP) and the loss of retinal ganglion cells (RGCs). Selecting suitable animals for preclinical models is of great significance in research on the prevention, early screening, and effective treatments of glaucoma. Rabbit eyeballs possess similar vascularity and aqueous humor outflow pathways to those of humans. Thus, they are among the earliest in vivo models used in glaucoma research. Over the years, rabbit models have made substantial contributions to understanding glaucomatous pathophysiology, surgical adaptations, biomedical device development, and drug development for reducing IOP, protecting RGCs, and inhibiting fibrosis. Compared to other animals, rabbits fit better with surgical operations and cost less. This review summarizes the merits and demerits of different ways to produce glaucomatous rabbit models, such as intracameral injection, vortex vein obstruction, Trendelenburg position, laser photo-coagulation, glucocorticoid induction, limbal buckling induction, retinal ischemia–reperfusion models, and spontaneous models. We analyzed their mechanisms in the hope of providing more references for experimental design and promoting the understanding of glaucoma treatment strategies.
Acquired immune deficiency syndrome (AIDS) is the name used to describe several potentially life-threatening infections and disorders that happen when HIV has severely compromised the immune system. The primary effect of HIV is to decrease host immunity, exposing the host to external pathogens. The development of pharmaceutical drugs that directly cure the infection is crucial because of the current wide-ranging epidemic of HIV. Most therapeutic anti-HIV drugs are nucleosides. However, their high toxicity and potential for drug resistance restrict their use. Many of the most effective clinical drugs used to inhibit HIV, the activation of latent HIV, and AIDS have been obtained from natural sources. This review focuses on potential natural medicinal products for treating and managing HIV and AIDS. Notwithstanding, further clinical research studies are needed to understand the subject and its dynamics.
Background: Medulloblastoma (MB) is one of the most common malignant brain tumors that mainly affect children. Various approaches have been used to model MB to facilitate investigating tumorigenesis. This study aims to compare the recapitulation of MB between subcutaneous patient-derived xenograft (sPDX), intracranial patient-derived xenograft (iPDX), and genetically engineered mouse models (GEMM) at the single-cell level.
Methods: We obtained primary human sonic hedgehog (SHH) and group 3 (G3) MB samples from six patients. For each patient specimen, we developed two sPDX and iPDX models, respectively. Three Patch+/− GEMM models were also included for sequencing. Single-cell RNA sequencing was performed to compare gene expression profiles, cellular composition, and functional pathway enrichment. Bulk RNA-seq deconvolution was performed to compare cellular composition across models and human samples.
Results: Our results showed that the sPDX tumor model demonstrated the highest correlation to the overall transcriptomic profiles of primary human tumors at the single-cell level within the SHH and G3 subgroups, followed by the GEMM model and iPDX. The GEMM tumor model was able to recapitulate all subpopulations of tumor microenvironment (TME) cells that can be clustered in human SHH tumors, including a higher proportion of tumor-associated astrocytes and immune cells, and an additional cluster of vascular endothelia when compared to human SHH tumors.
Conclusions: This study was the first to compare experimental models for MB at the single-cell level, providing value insights into model selection for different research purposes. sPDX and iPDX are suitable for drug testing and personalized therapy screenings, whereas GEMM models are valuable for investigating the interaction between tumor and TME cells.
Background: Over the past 50 years, the incidence of obesity has gradually increased, necessitating investigation into the multifactorial contributors to this disease, including the gut microbiota. Bacteria within the human gut microbiome communicate using a density-dependent process known as quorum sensing (QS), in which autoinducer (AI) molecules (e.g., N-acyl-homoserine lactones [AHLs]) are produced to enable bacterial interactions and regulate gene expression.
Methods: We aimed to disrupt QS using quorum quenching (QQ) lactonases GcL and SsoPox, which cleave AHL signaling molecules in a taxa-specific manner based on differing enzyme affinities for different substrates. We hypothesized that QQ hinders signals from obesity-associated pathobionts, thereby slowing or preventing obesity.
Results: In a murine model of diet-induced obesity, we observed GcL and SsoPox treatments have separate sex-dependent and dose-dependent effects on intestinal community composition and diversity. Notably, male mice given 2 mg/mL SsoPox exhibited significant changes in the relative abundances of gram-negative taxa, including Porphyromonadaceae, Akkermansiaceae, Muribaculaceae, and Bacteroidales (Kruskal–Wallis p < 0.001). Additionally, we used covariance matrix network analysis to model bacterial taxa co-occurrence due to QQ enzyme administration. There were more associations among taxa in control mice, particularly among gram-negative bacteria, whereas mice receiving SsoPox had the fewest associations.
Conclusions: Overall, our study establishes proof of concept that QQ is a targetable strategy for microbial control in vivo. Further characterization and dosage optimization of QQ enzymes are necessary to harness their therapeutic capability for the treatment of chronic microbial-associated diseases.
Background: The aim was to elucidate the function of IL-37 in middle east respiratory syndrome coronavirus (MERS-CoV) infection, thereby providing a novel therapeutic strategy for managing the clinical treatment of inflammatory response caused by respiratory virus infection.
Methods: We investigated the development of MERS by infecting hDPP4 mice with hCoV-EMC (107 TCID50 [50% tissue culture infectious dose]) intranasally. We infected A549 cells with MERS-CoV, which concurrently interfered with IL-37, detecting the viral titer, viral load, and cytokine expression at certain points postinfection. Meanwhile, we administered IL-37 (12.5 μg/kg) intravenously to hDPP4 mice 2 h after MERS-CoV-2 infection and collected the serum and lungs 5 days after infection to investigate the efficacy of IL-37 in MERS-CoV infection.
Results: The viral titer of MERS-CoV-infected A549 cells interfering with IL-37 was significantly reduced by 4.7-fold, and the viral load of MERS-CoV-infected hDPP4 mice was decreased by 59-fold in lung tissue. Furthermore, the administration of IL-37 suppressed inflammatory cytokine and chemokine (monocyte chemoattractant protein 1, interferon-γ, and IL-17A) expression and ameliorated the infiltration of inflammatory cells in hDPP4 mice.
Conclusion: IL-37 exhibits protective properties in severe pneumonia induced by MERS-CoV infection. This effect is achieved through attenuation of lung viral load, suppression of inflammatory cytokine secretion, reduction in inflammatory cell infiltration, and mitigation of pulmonary injury.
Background: The mechanisms underlying cardiac remodeling in aortic valvular (AoV) disease remain poorly understood, partially due to the insufficiency of appropriate preclinical animal models. Here, we present a novel murine model of aortic regurgitation (AR) generated by trans-apical wire destruction of the AoV.
Methods: Directed by echocardiography, apical puncture of the left ventricle (LV) was performed in adult male C57BL/6 mice, and a metal guidewire was used to induce AoV destruction. Echocardiography, invasive LV hemodynamic and histological examination were conducted to assess the degree of AR, LV function and remodeling.
Results: AR mice exhibited rapid aortic regurgitation velocity (424 ± 15.22 mm/s) immediately following successful surgery. Four weeks post-surgery, echocardiography revealed a 54.6% increase in LV diastolic diameter and a 55.1% decrease in LV ejection fraction in AR mice compared to sham mice. Pressure-volume catheterization indicated that AR mice had significantly larger LV end-diastolic volumes (66.2 ± 1.5 μL vs. 41.8 ± 3.4 μL), reduced LV contractility (lower dP/dtmax and Ees), and diminished LV compliance (smaller dP/dtmin and longer Tau) compared to sham mice. Histological examination demonstrated that AR mice had significantly larger cardiomyocyte area and more myocardial fibrosis in LV tissue, as well as a 107% and a 122% increase of heart weight/tibial length and lung weight/tibial length, respectively, relative to sham mice.
Conclusions: The trans-apex wire-induced destruction of the AoV establishes a novel and efficient murine model to develop AR, characterized by significant eccentric LV hypertrophy, heart failure, and pulmonary congestion.
Background: Scientific animal models are indispensable for studying trauma repair. This work aimed at establishing a more scientific rat trauma model by studying different rat trauma models caused by different trauma numbers, locations, and trauma attachment tension unloaders and rat age.
Methods: A four-trauma self-upper, lower, left and right control model; a two-trauma self-trauma bare and ring control model; and a young and old rat trauma model were created to evaluate the condition of these traumas.
Results: In the four-trauma self-control model, the healing status of the upper proximal cephalic trauma was better than that of the lower proximal caudal trauma, whereas there was no significant difference between the left and right trauma. The healing rate and postwound condition of the trauma with a ring control in the two-trauma model were better than those of the bare side. The healing speed of the old rats was slower, and the amount of extracellular matrix in the subcutaneous tissue after healing was significantly lower than that of the young rats.
Conclusion: The double trauma with a ring is a more scientific and reasonable experimental model. There is a significant difference between young and old rats in the wound healing process. Therefore, the appropriate age of the rats should be selected according to the main age range of the patients with similar conditions in the clinical setting being mimicked.
Background: Makorin ring finger protein 3 gene (MKRN3) gene mutation is the most common genetic cause of central precocious puberty (CPP) in children. Due to the lack of ideal MKRN3-modified animal model (MKRN3-modified mice enter puberty only 4–5 days earlier than normal mice), the related research is limited.
Methods: Therefore, the MKRN3-modified rabbit was developed using CRISPR (clustered regularly interspaced short palindromic repeats) gene editing technology. The genotype identification and phenotype evaluation of MKRN3-modified rabbits were carried out.
Results: The first estrus of MKRN3-modified female rabbits was observed ~27 days earlier than that of wild-type female rabbits, with a typical CPP phenotype. This study found increased gonadotropin releasing hormone (GnRH) and decreased gonadotropin inhibiting hormone (GnIH) in the hypothalamus of the CPP rabbit model with MKRN3 gene mutation. Although this study failed to fully clarify the pathogenesis of CPP caused by MKRN3 mutation, it found some differentially expressed genes and potential pathways through transcriptome sequencing.
Conclusions: This study established a novel CPP model: paternal MKRN3 gene-modified rabbit. It is hoped that the establishment of this model will help researchers better understand, treat, and prevent CPP in the future.
Background: Aortic atherosclerosis increases the risk of embolic events under extracorporeal circulation (ECC). To evaluate the hemodynamic impact of ECC on atheromatous plaques, an atherosclerosis animal model, which is also eligible for ECC, is required.
Methods: Twenty-nine New Zealand White rabbits received a pro-atherosclerotic diet (group diet, n = 10), a pro-atherosclerotic diet and additional intraaortic balloon insufflation injury (group BI, n = 9), or served as controls (n = 10). After 3 or 6 months, aortic explants were analyzed by (immuno-) histology and RT-PCR.
Results: Blood serum analyses revealed increased cholesterol-levels in groups diet and BI compared to controls (3 months: p = 0.03 each, 6 months: p < 0.0001 each). Aortic inflammatory infiltration was significantly enhanced in groups diet (CD3 at 3 months: p < 0.0001, 6 months: p = 0.02; CD68 at 3 months: p = 0.01) and BI (CD3 at 3 months: p < 0.0001, 6 months: p = 0.03; CD68 at 3 months: p = 0.04, 6 months: p = 0.02). Increased intima hyperplasia occurred in both groups (p < 0.0001 each). Macroscopic analyses after 3 and 6 months showed ubiquitous lumen-narrowing aortic plaques. Calcification of the intima and media was increased in groups diet (intima: p < 0.0001 at 3 and 6 months; media at 3 months: p < 0.0001, 6 months: p = 0.01) and BI (intima: p < 0.0001 at 3 and 6 months; media at 3 months: p < 0.0001, 6 months: p = 0.02). Extensive lipid accumulation was found in the intima in both treatment groups (p < 0.0001 each).
Conclusions: A rabbit model with high aortic calcific plaque burden—diet-induced with no implicit need of an additional intimal injury by an intraaortic balloon insufflation due to comparable outcome—exhibiting multiple pathophysiological aspects of human atherosclerosis has been designed and thoroughly characterized. It is suitable for use in future studies on the interaction between atherosclerotic plaques and the arterial blood flow under ECC.
Background: This study evaluates the efficacy of gabexate mesylate thermosensitive in-situ gel (GMTI) in the treatment of beagle grade III pancreatic trauma (PT) with the assistance of contrast-enhanced ultrasound (CEUS) and investigates its mechanism of action.
Methods: A grade III PT model consisting of 15 beagle dogs with severed main pancreatic ducts was created and treated with cephalic vein injection of gabexate mesylate (GM) (1.54 mL/10 kg, TID) and peripancreatic injection of GMTI (4.63 mL/10 kg, QD) guided by CEUS within 24 h post-surgery. Ascites and serum levels of amylase (AMY), lipase (LPS), C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and urinary trypsinogen activating peptide (TAP) were detected by ELISA. Histopathological changes in the canine pancreas were observed by Hematoxylin and Eosin staining.
Results: CEUS accurately displayed pancreatic lesions and guided catheterisation. Compared to the control group, the ascites was significantly reduced after treatment (p < 0.01). AMY and LPS ascites significantly decreased on post-operative 1st and 2nd day (p < 0.01). The levels of AMY, LPS, CRP, IL-6, and TNF-α in serum were decreased (p < 0.05 or p < 0.01). Urinary TAP was decreased 1 and 2 days after treatment (p < 0.05 or p < 0.01, respectively). In the control group, pancreatic tissue necrosis was evident in the wound area. Normal glandular cell structures and fibrous tissue hyperplasia were observed in the wound area after GMTI treatment. The GMTI group performed better than the GM group in improving pancreatic histology and reducing AMY levels in the early post-operative period.
Conclusion: Guided by CEUS, daily peripancreatic injections of GMTI in Beagles effectively inhibit pancreatic enzyme activity and aid in the adjuvant treatment of pancreatic trauma.
Background: In view of the ever-increasing representation of Staphylococcus spp. strains resistant to various antibiotics, the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.
Methods: In this article, we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical antimicrobial agents that matches the real clinical situation. The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.
Results: In the final model, 10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia, with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension. One pig was not inoculated and used as the negative control. Subsequently, the bandages were changed on Days 4, 8, 11, and 15. At these time points, a filter paper imprint technique (FPIT) was made from each wound for semi-quantitative microbiological evaluation. Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological, histopathological, and molecular-biological examination. The infection with the inoculated S. aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples. The dynamics of the inflammatory markers and clinical signs of infection are also described.
Conclusions: A successfully developed porcine model is suitable for in vivo testing of novel short-acting topical antimicrobial agents.
The high morbidity and mortality of colorectal cancer (CRC) is a major challenge in clinical practice. Although a series of alternative research models of CRC have been developed, appropriate orthotopic animal models that reproduce the specific clinical response as well as pathophysiological immune features of CRC are still lacking. In the current study, we constructed a CRC orthotopic xenograft model by implanting the tumor tubes at the colorectum of mice and monitored the model development using bioluminescence imaging. This model successfully recapitulates the clinical chemotherapy efficacy, including reduced total flux, tumor weight, and the expression of Ki67 after treatment of the first-line chemotherapy regime of CRC (FOLFOX: oxaliplatin and 5-fluorouracil/calcium folinate). The model also reproduced the immunosuppressive effect of FOLFOX, indicated by decreased infiltration of macrophages and increased Treg cells in tumor. Additionally, the orthotopic xenograft approach may be applied in immunodeficient NCG/NSG mice for constructing patient-derived xenografts, and being used in clinical precision medicine and drug evaluation. We believe the current model is a successful surgical orthotopic xenograft approach for cancer research and deserves to be popularized, which will provide a convenient and efficient platform for in-depth mechanism exploration of CRC and preclinical drug evaluation.
This study aimed to investigate the impact of administration routes in establishing the Adriamycin (ADR)-induced chronic kidney disease (CKD) model. Using BALB/c mice, we compared the effects of conventional tail-vein injection (TV10, 10 mg/kg) to those of retro-orbital sinus (orbital vein) injection (OV10, 10 mg/kg; OV8, 8 mg/kg). The results indicated that the OV10 group exhibited CKD pathology similar to the TV10 group, with both groups demonstrating significantly higher urinary albumin/creatinine ratio (p < 0.05), tubular injury (p < 0.05), and degree of renal fibrosis (p < 0.05) than the OV8 group. No significant differences were observed between the OV10 and TV10 groups in urinary albumin/creatinine ratio, tubular injury, and degree of renal fibrosis. These findings demonstrated that retro-orbital administration of 10 mg/kg ADR induces comparable effects to conventional tail-vein administration. This technique's technical simplicity may improve experimental efficiency, reproducibility, and animal welfare in CKD research. In conclusion, this study validates the utility of retro-orbital injection in CKD model establishment, demonstrating its potential to standardize and improve the reliability of future CKD research protocols.
The mortality rate of patients with abdominal aortic aneurysm (AAA) after rupture is extremely high, and this disease has become an important disease endangering the health of the Chinese population. Methods used to model AAA include intraluminal pressurized elastase infusion, chronic infusion of angiotensin II (Ang II) via an osmotic pump, periarterial application of calcium chloride, vascular grafting, and gene modification. AAA models induced by elastase and Ang II are the two most widely used animal models. In the elastase-induced model, because intraluminal infusion is transient, with the cessation of initial stimulation, the aneurysm lesion tends to be stable and rarely ruptures. The model induced by Ang II infusion often presents with a typical aortic dissection with a false lumen, whereas clinical AAA patients do not necessarily have dissection. Currently, the treatment of AAA in clinical practice remains endovascular, and there is a lack of pharmacological therapy, which is also related to the fact that the pathogenic mechanism has not been fully elucidated. Smoking, old age, male sex, and hypertension are the main risk factors for AAA, but these risk factors have not been fully investigated in the current modeling methods, which may affect the clinical translational application of research results based on animal models. Therefore, this article reviews the most commonly used AAA modeling methods, comments on their applications and limitations, and provides a perspective on the development of novel animal models.