ZHENG Ying-ying, LIU Zi-shen, ZHANG Jing-zhi, YUAN Meng-qi, ZHANG Yu-tong, LU Tai-cheng, PAN Yuan-can, YOU Jia-feng, WANG Jue, M Iqbal Choudhary, ZHANG Gan-lin, YANG Guo-wang
Background:Higher platelet levels are common in advanced tumor patients.It affects the progression and prognosis of cancer.Objectives:We attempted to identify the optimal method for establishing a murine model of lung metastatic melanoma with elevated platelets,and thus to provide a reasonable and stable simulative environment in vivo for investigating the role of platelets in the hematogenous metastasis of malignant melanoma.Methods:The platelet levels were elevated either through injection of platelets or the injection of murine recombinant thrombopoietin (TPO).Then,B16 F10 cells were injected in situ and via tail vein to develop an advanced melanoma model with elevated platelets.In the control group,mice were inoculated with B16 cells in the same manner as above.Following the tumor induction,dynamic recording captured the physiological and pathological indexes across the different groups.Upon completion of sampling,variations of indicators were compared.Results:The washed platelets and TPO were found to elevate platelets in mice (P<0.05).Compared to control group,elevated platelets(stimulated by TPO) promoted the formation of lung metastasis while inhibited the growth of subcutaneous tumor (P<0.05).The presence of tumor embolus and thrombus in the lungs may contribute to the decrease of platelets observed in the later stage.Multiple injections of platelets may lead to hyperactive peripheral immunity,probably related to infection and allogeneic infusion,which may exert some limitations on the research of tumor immune microenvironment.Conclusion:Endogenous platelet supplementation is more suitable for developing an advanced melanoma model with elevated platelets,effectively facilitating the exploration of tumor microenvironment in melanoma.
Objective:FBJ Murine Osteosarcoma Viral Oncogene Homolog B (FosB) is a member of the Fos gene family and plays an important role in transcriptional activation and tumor transformation.Recent studies have shown that the dysregulation of FosB expression is associated with the pathogenesis of a variety of lymphomas.However,the role of FosB in lymphocyte generation and function is still unclear.Methods:In this study,the expression level of FosB mRNA during B cell development was first detected.we generated FosB-knockout(KO) mice and bone marrow (BM) chimeric mice in which FosB is deleted in all of mature B cells.Study on the role of FosB in B cell hematopoietic reconstruction through competitive bone marrow transplantation experiments.We also studied the effects of FosB on B cell proliferation,differentiation,function,and MAPK pathway after BCR induced activation by purifying mature B cells from the spleen.Results:We discovered that FosB deficiency in mice barely affected early development of B cells but markedly reduced marginal zone (MZ) B cells in the spleen.Studies of BM chimeric mice also demonstrated that FosB is required in a cell-intrinsic manner to maintain normal MZ B-cell development.Moreover,FosB deficiency reduced BCR-induced B cell proliferation and survival.FosB deficiency also result in significant changes in basal antibody levels and B cell antibody responses.Furthermore,FosB deficiency specifically impaired Notch2pathway and BCR-induced activation of the MAPK pathway in mature B cells,respectively.Conclusion:FosB plays a critical and distinct role in mature B-cell immune response and development of MZ B cells.
The aging of the social population has drawn much attention to the etiology, prevention and treatment of neurodegenerative diseases such as Alzheimer's Disease(AD) and Vascular Dementia(VD). Chronic Cerebral Hypoperfusion(CCH), which is long-term associated with chronic diseases that are highly prevalent among middle-aged and elderly people, such as hyperglycemia, hypertension, hyperlipidemia, atherosclerosis, heart failure, and metabolic syndrome, has become a potential risk factor for the occurrence and development of these diseases. Some studies have found that CCH can aggravate the pathological changes related to AD, including β-amyloid protein deposition and tau protein hyperphosphorylation, indicating that chronic hypoperfusion might not only be an important pathogenic factor for vascular cognitive impairment, but also play a promoting role in the course of AD. This makes stable and reliable animal models of CCH important research tools for the early study of neurodegenerative diseases, the study of potential risk factors, and early prevention and treatment strategies. CCH could lead to structural and functional disorders of neurovascular units and induce cognitive dysfunction. Currently, widely adopted models include Two-Vessel Occlusion in rats. The 2VO model and the Bilateral Common Carotid Artery Stenosis(BCAS) model in mice. Furthermore, the Asymmetric Carotid Artery Stenosis(ACAS) and non-human primate ThreeVessel Occlusion(3VO) models are closer to human pathology compared to the rodent models. The 2VO model is simple to operate but prone to optic nerve ischemia. The BCAS model is delicate and difficult to operate, but more stable and long-lasting of perfusion. The ACAS model has a low mortality rate, but the induction method is complex. The 3VO model can simulate human ischemic cerebral small vessel disease, but the cost is high. The success of model establishment and its impact on brain function can be evaluated through cerebral blood flow detection, behavioral assessment and histopathological analysis. The cerebral blood flow significantly decreased to 30%~50% of the initial level after the operation. Although it recovered slowly within several weeks, it remained persistently below the normal level, causing continuous hypoperperfusion of the brain tissue and resulting in a series of injuries. In behavioral tests such as the Morris water maze experiment, animals may show prolonged latency, prolonged distance, etc. The pathological morphology is mainly manifested as ischemic injury of the white matter of the brain, including demyelination and axonal damage, as well as apoptosis of oligodendrocytes and excessive activation of microglia and/or astrocytes. However, the gray matter regions of the cortex and hippocampus are different from the severe lesions of AD or VD, presenting only with mild neuronal loss. Furthermore, whether the integrity of the Blood-Brain Barrier(BBB) is damaged is also an important evaluation index. CCH can increase the permeability of the BBB, thereby leading to dysfunction of the neurovascular unit and aggravating brain tissue damage. CCH animal models play a significant role in the exploration of the mechanisms of neurodegenerative diseases, the mechanisms of complications of "three highs", and the development of drugs for the prevention and treatment of these diseases. Through the CCH model, not only can the pathological processes such as white matter degeneration, neuroinflammation and BBB destruction in brain tissue be clarified, but also the pathogenesis of vascular cognitive impairment can be deeply understood; Screening and evaluation of candidate drugs and cell therapy regimens can also be conducted to explore effective strategies for improving cognitive impairment caused by hypoperfusion.
Alzheimer's disease(AD) is a prevalent neurodegenerative disease that poses a serious threat to the health of the elderly. The pathogenesis of AD is complex and not yet fully prevalent. Establishing appropriate animal models is of great significance for the indepth investigation of its pathogenesis and the search for effective therapeutic strategies. In recent years, various animal models of AD have been commonly used, including natural models, genetically engineered models, and chemically induced models. Each of them has its advantages and disadvantages in simulating the pathological features and cognitive dysfunction of AD. And this requires the application of different animals, such as mice, rats, and non-human primates for AD research. Mouse models are extensively utilized owing to their significant advantages. Their genomes show a high degree of similarity to those of humans, enabling them to effectively replicate the genetic basis of the disease. Mice are small in size, have rapid reproductive cycles, and possess short lifespans, making them ideal for large-scale and long-term studies. Moreover, their genetic manipulation techniques are well-established, providing a diverse array of model options that serve as a robust foundation for disease simulation and mechanistic research. Additionally, cognitive behavior analysis in mice is straightforward and can be closely correlated with pathological changes in the brain, thereby facilitating the evaluation of disease progression and therapeutic efficacy. Mouse models such as Tg2576, 5xFAD and 3xTg-AD, by simulating the pathological features and cognitive dysfunction of human AD, provide an important foundation for studying the pathogenesis of AD, drug screening and the development of treatment methods. Compared with mice, rats exhibit greater physiological and genetic similarity to humans. Their larger body and brain volume make experimental operations more convenient, including intrathecal administration, microdialysis, multiple samplings, and in vivo electrophysiological studies. Furthermore, rats' motor coordination and behavioral patterns are closer to those of humans, allowing for a more comprehensive assessment of the impact of AD on behavior. The TgF344-AD rat model, a double transgenic model carrying two human gene mutations, displays neuropathological changes similar to those observed in human AD. In addition, the Mac mulacaatta, as a non-human primate model, holds unique advantages in AD research. With a longer lifespan, it permits long-term longitudinal studies to observe the development process of AD. By injecting adeno-associated viruses carrying specific tau mutations into the brains of Macaca mulatta, tau pathological changes similar to those in AD can be induced, encompassing the misfolding, phosphorylation, aggregation of tau proteins, and the formation of neurofibrillary tangles. Zebrafish, highly similar to humans in terms biology of, structure, function, and genetics, has emerged as an extremely attractive model for studying human diseases. It is small in size, has a high reproductive capacity, is easy to breed, and its embryos and larvae are transparent, making it suitable for high-throughput drug screening. In conclusion, different animal models each possess their own distinct characteristics and advantages. Future research should integrate the strengths of multiple models to more comprehensively simulate the complex pathological process of human AD and thereby promote the development of effective treatment methods.