Induction Murine Models of Chronic Fatigue Syndrome by Brucella abortus Antigen Injections: Is Anemia Induced or Not?

Abstract:

To investigate whether Brucella abortus (BA) antigen injections lead to anemia, and to establish an appropriate Chronic Fatigue Syndrome (CFS) animal model by BA injections, 6 repeated injections of BA antigen were fulfilled every 2 weeks. At a high dose of 1∗10(10) particles/mouse, anemia was induced within 2 weeks and then recovered a lot at the end of the research, while at a moderate dose of 1∗10(8) (3 injections) shifting to 1∗10(9)/mouse (3 injections) anemia was absent. In both groups running wheel activity remained very low even 6 weeks after the last injection.

 

Source: Moriya J, He Q, Uenishi H, Akazawa S, Yamakawa J, Kobayashi J, Ishigaki Y. Induction Murine Models of Chronic Fatigue Syndrome by Brucella abortus Antigen Injections: Is Anemia Induced or Not? Biomed Res Int. 2015;2015:191489. doi: 10.1155/2015/191489. Epub 2015 Jun 11. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4480237/ (Full article)

 

Hochu-ekki-to combined with interferon-gamma moderately enhances daily activity of chronic fatigue syndrome mice by increasing NK cell activity, but not neuroprotection

Abstract:

The purpose of this study was to evaluate the beneficial effect of Hochu-ekki-to (TJ-41) combined with interferon-gamma (IFN gamma) on daily activity, immunological and neurological alternation in a mouse model of chronic fatigue syndrome (CFS).

CFS was induced by 6 times of repeated injection of Brucella abortus antigen every 2 weeks. Both single TJ-41 and TJ-41 combined with IFN gamma increased running activity and thymus weight of CFS mice, while thicker thymic cortex together with elevation of natural killer cell activity was only found in the combined treatment group. No significant improvement was observed in the atrophic brain and decreased expression level of brain-derived neurotrophic factor and Bcl-2 mRNA in hippocampus in both treatment groups.

Our results suggest that TJ-41 combined with IFN gamma might have a protective effect on the marked reduction in the activity in a model of CFS via normalization of host immune responses, but not neuroprotection.

 

Source: Chen R, Moriya J, Luo X, Yamakawa J, Takahashi T, Sasaki K, Yoshizaki F. Hochu-ekki-to combined with interferon-gamma moderately enhances daily activity of chronic fatigue syndrome mice by increasing NK cell activity, but not neuroprotection. Immunopharmacol Immunotoxicol. 2009 Jun;31(2):238-45. doi: 10.1080/08923970802391525.https://www.ncbi.nlm.nih.gov/pubmed/18791913

 

Brain atrophy in a murine model of chronic fatigue syndrome and beneficial effect of Hochu-ekki-to (TJ-41)

Abstract:

Brain-derived neurotrophic factor (BDNF) is associated with the main symptoms of chronic fatigue syndrome (CFS) and neuron apoptosis. Nevertheless, no study has been performed directly to explore the relationship between CFS, BDNF and neuron apoptosis.

We induced a CFS model by six injections of killed Brucella abortus antigen in BALB/c mice and treated them with Hochu-ekki-to (TJ-41). Daily running activity, body weight (BW), ratio of cerebral weight to BW (CW/BW) and expression levels of BDNF and Bcl-2 mRNA in the hippocampus were determined. The daily activity and CW/BW decreased significantly in the CFS model. BDNF and Bcl-2 mRNA expression levels in the hippocampus were suppressed in the CFS model and TJ-41 treated mice, while no significant difference was found between them.

We improved a murine model to investigate the relationship between CFS and brain dysfunction. In this model, reduced daily activity might have been associated with decreased hippocampal BDNF mRNA expression, hippocampal apoptosis and brain atrophy. TJ-41 increased the daily running activity of the model, which was independent of brain recovery.

 

Source: Chen R, Moriya J, Yamakawa J, Takahashi T, Li Q, Morimoto S, Iwai K, Sumino H, Yamaguchi N, Kanda T. Brain atrophy in a murine model of chronic fatigue syndrome and beneficial effect of Hochu-ekki-to (TJ-41). Neurochem Res. 2008 Sep;33(9):1759-67. doi: 10.1007/s11064-008-9620-1. Epub 2008 Mar 4. https://www.ncbi.nlm.nih.gov/pubmed/18317925

 

Mouse running activity is lowered by Brucella abortus treatment: a potential model to study chronic fatigue

Abstract:

Chronic fatigue syndrome, which can occur after acute infection and last for years, is characterized by severe and persistent fatigue. Others have reported decreases in mouse running activity following infection and have suggested this may provide an animal model for studying chronic fatigue.

Voluntary running is a highly motivated activity in mice, which will often run 5-7 mi/day in our laboratory. Following 2 weeks of acclimation to running wheels with food and water available ad lib, female BALB/c mice received 0.2-mL tail vein injections of killed Brucella abortus (BA) or saline vehicle. Subsequently the effects on voluntary running and grooming behavior were determined.

Injection of BA caused an immediate large decrease in running and a lack of grooming. Vehicle injections produced no changes in behavior. After the first several days of reduced running behavior, levels of running and grooming slowly returned back to normal over the next 2-4 weeks, with substantial individual differences in the rate of recovery.

The pattern of running during recovery was intriguing in that BA mice first ran at normal levels just after the lights went out, but they stopped after only 1-2 h. As recovery proceeded, they gradually increased the duration of the running bout during the night. Because this model uses voluntary exertion and the ability to run for longer periods of time characterizes recovery, the model may be a good one for studying the biologic underpinnings of chronic fatigue.

 

Source: Ottenweller JE, Natelson BH, Gause WC, Carroll KK, Beldowicz D, Zhou XD, LaManca JJ. Mouse running activity is lowered by Brucella abortus treatment: a potential model to study chronic fatigue. Physiol Behav. 1998 Mar;63(5):795-801. http://www.ncbi.nlm.nih.gov/pubmed/9618001